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1
Banchi, Leonardo, Enrico Compagno, Vladimir Korepin y Sougato Bose. "Quantum gates between distant qubits via spin-independent scattering". Quantum 1 (30 de noviembre de 2017): 36. http://dx.doi.org/10.22331/q-2017-11-30-36.
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We show how the spin independent scattering of two initially distant qubits, say, in distinct traps or in remote sites of a lattice, can be used to implement an entangling quantum gate between them. The scattering takes place under 1D confinement for which we consider two different scenarios: a 1D wave-guide and a tight-binding lattice. We consider models with contact-like interaction between two fermionic or two bosonic particles. A qubit is encoded in two distinct spins (or other internal) states of each particle. Our scheme enables the implementation of a gate between two qubits which are initially too far to interact directly, and provides an alternative to photonic mediators for the scaling of quantum computers. Fundamentally, an interesting feature is that "identical particles" (e.g., two atoms of the same species) and the 1D confinement, are both necessary for the action of the gate. Finally, we discuss the feasibility of our scheme, the degree of control required to initialize the wave-packets momenta, and show how the quality of the gate is affected by momentum distributions and initial distance. In a lattice, the control of quasi-momenta is naturally provided by few local edge impurities in the lattice potential.
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Arsen'ev, A. A. "Resonance scattering in quantum wave guides". Sbornik: Mathematics 194, n.º 1 (28 de febrero de 2003): 1–19. http://dx.doi.org/10.1070/sm2003v194n01abeh000703.
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Zagoskin, A. M. "d-Wave superconductors and quantum computers". Physica C: Superconductivity 368, n.º 1-4 (marzo de 2002): 305–9. http://dx.doi.org/10.1016/s0921-4534(01)01186-8.
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Maglione, Enrico, Lídia S. Ferreira y Giorgio Cattapan. "Asymptotic properties of bound states in coupled quantum wave guides". Journal of Physics A: Mathematical and General 39, n.º 5 (18 de enero de 2006): 1207–28. http://dx.doi.org/10.1088/0305-4470/39/5/013.
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Borri, P., W. Langbein, J. M. Hvam, F. Heinrichsdorff, M. H. Mao y D. Bimberg. "Coherent versus incoherent dynamics in InAs quantum-dot active wave guides". Journal of Applied Physics 89, n.º 11 (junio de 2001): 6542–44. http://dx.doi.org/10.1063/1.1367410.
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Post, Olaf. "Branched quantum wave guides with Dirichlet boundary conditions: the decoupling case". Journal of Physics A: Mathematical and General 38, n.º 22 (18 de mayo de 2005): 4917–31. http://dx.doi.org/10.1088/0305-4470/38/22/015.
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Sugisaki, Kenji, Shigeaki Nakazawa, Kazuo Toyota, Kazunobu Sato, Daisuke Shiomi y Takeji Takui. "Quantum chemistry on quantum computers: quantum simulations of the time evolution of wave functions under the S2 operator and determination of the spin quantum number S". Physical Chemistry Chemical Physics 21, n.º 28 (2019): 15356–61. http://dx.doi.org/10.1039/c9cp02546d.
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A quantum circuit to simulate time evolution of wave functions under an S2 operator is provided, and integrated it to the quantum phase estimation circuit to calculate the spin quantum number S of arbitrary wave functions on quantum computers.
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Wang, Yazhen, Shang Wu y Jian Zou. "Quantum Annealing with Markov Chain Monte Carlo Simulations and D-Wave Quantum Computers". Statistical Science 31, n.º 3 (agosto de 2016): 362–98. http://dx.doi.org/10.1214/16-sts560.
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Barnes, C., B. L. Johnson y G. Kirczenow. "Introducing directionality to Anderson localization: The transport properties of quantum railroads". Canadian Journal of Physics 72, n.º 9-10 (1 de septiembre de 1994): 559–67. http://dx.doi.org/10.1139/p94-071.
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We present a study of the transport properties of a general class of quantum mechanical wave guides: quantum railroads (QRR). These wave guides are characterized by having adiabatic modes that carry current along the wave guide in opposite directions; for example N forward modes and M reverse modes. Anderson localization and the integer quantum Hall effect are characteristic of the disordered N = M and M = 0 cases, respectively. We consider the general case of arbitrary N and M, and show that it can be understood in terms of directed localization. Thus, we unify the theories of Anderson localization and the integer quantum Hall effect and demonstrate how they fit into a broader conceptual framework. We find that in any QRR there are always [Formula: see text] perfectly transmitted effective adiabatic modes with the remainder being subject to multiple scattering and interference effects characteristic of the N = M case.
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Sugisaki, Kenji, Shigeaki Nakazawa, Kazuo Toyota, Kazunobu Sato, Daisuke Shiomi y Takeji Takui. "Quantum Chemistry on Quantum Computers: A Method for Preparation of Multiconfigurational Wave Functions on Quantum Computers without Performing Post-Hartree–Fock Calculations". ACS Central Science 5, n.º 1 (31 de diciembre de 2018): 167–75. http://dx.doi.org/10.1021/acscentsci.8b00788.
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Korolyov, Vyacheslav y Oleksandr Khodzinskyi. "Solving Combinatorial Optimization Problems on Quantum Computers". Cybernetics and Computer Technologies, n.º 2 (24 de julio de 2020): 5–13. http://dx.doi.org/10.34229/2707-451x.20.2.1.
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Introduction. Quantum computers provide several times faster solutions to several NP-hard combinatorial optimization problems in comparison with computing clusters. The trend of doubling the number of qubits of quantum computers every year suggests the existence of an analog of Moore's law for quantum computers, which means that soon they will also be able to get a significant acceleration of solving many applied large-scale problems. The purpose of the article is to review methods for creating algorithms of quantum computer mathematics for combinatorial optimization problems and to analyze the influence of the qubit-to-qubit coupling and connections strength on the performance of quantum data processing. Results. The article offers approaches to the classification of algorithms for solving these problems from the perspective of quantum computer mathematics. It is shown that the number and strength of connections between qubits affect the dimensionality of problems solved by algorithms of quantum computer mathematics. It is proposed to consider two approaches to calculating combinatorial optimization problems on quantum computers: universal, using quantum gates, and specialized, based on a parameterization of physical processes. Examples of constructing a half-adder for two qubits of an IBM quantum processor and an example of solving the problem of finding the maximum independent set for the IBM and D-wave quantum computers are given. Conclusions. Today, quantum computers are available online through cloud services for research and commercial use. At present, quantum processors do not have enough qubits to replace semiconductor computers in universal computing. The search for a solution to a combinatorial optimization problem is performed by achieving the minimum energy of the system of coupled qubits, on which the task is mapped, and the data are the initial conditions. Approaches to solving combinatorial optimization problems on quantum computers are considered and the results of solving the problem of finding the maximum independent set on the IBM and D-wave quantum computers are given. Keywords: quantum computer, quantum computer mathematics, qubit, maximal independent set for a graph.
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Yin, Zhangqi y Zhaohui Wei. "Why quantum adiabatic computation and D-Wave computers are so attractive?" Science Bulletin 62, n.º 11 (junio de 2017): 741–42. http://dx.doi.org/10.1016/j.scib.2017.05.001.
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Delâge, A. "Modelling of semiconductor rib wave guides by a finite difference method". Canadian Journal of Physics 69, n.º 3-4 (1 de marzo de 1991): 512–19. http://dx.doi.org/10.1139/p91-084.
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The method of finite differences is used to solve the scalar wave equation for semiconductor rib wave guides. Boundary conditions derived from continuity relations are applied between regions of different refractive index, allowing more accurate evaluation of the propagation constants for ideal cases of abrupt change in the index. Also appropriate external boundary conditions alleviate the inaccuracy generally introduced by setting the field equal to zero on the external limit of the mesh. Our results agree with various other techniques when applied to typical guiding structures. As an example, we model a multiple-quantum-well structure by using an equivalent layered structure. Mode characteristics and confinement factors obtained by the method are of interest in understanding the behaviour of the lasers and modulators fabricated in our laboratory.
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Kirke, Alexis. "Programming gate-based hardware quantum computers for music". Muzikologija, n.º 24 (2018): 21–37. http://dx.doi.org/10.2298/muz1824021k.
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There have been significant attempts previously to use the equations of quantum mechanics for generating sound, and to sonify simulated quantum processes. For new forms of computation to be utilized in computer music, eventually hardware must be utilized. This has rarely happened with quantum computer music. One reason for this is that it is currently not easy to get access to such hardware. A second is that the hardware available requires some understanding of quantum computing theory. This paper moves forward the process by utilizing two hardware quantum computation systems: IBMQASM v1.1 and a D-Wave 2X. It also introduces the ideas behind the gate-based IBM system, in a way hopefully more accessible to computerliterate readers. This is a presentation of the first hybrid quantum computer algorithm, involving two hardware machines. Although neither of these algorithms explicitly utilize the promised quantum speed-ups, they are a vital first step in introducing QC to the musical field. The article also introduces some key quantum computer algorithms and discusses their possible future contribution to computer music.
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Sugisaki, Kenji, Satoru Yamamoto, Shigeaki Nakazawa, Kazuo Toyota, Kazunobu Sato, Daisuke Shiomi y Takeji Takui. "Quantum Chemistry on Quantum Computers: A Polynomial-Time Quantum Algorithm for Constructing the Wave Functions of Open-Shell Molecules". Journal of Physical Chemistry A 120, n.º 32 (8 de agosto de 2016): 6459–66. http://dx.doi.org/10.1021/acs.jpca.6b04932.
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Whitehead, N. J., W. P. Gillin, I. V. Bradley, B. L. Weiss y P. Claxton. "Disorder-induced mixing of InGaAs/InP multiple quantum wells by phosphorus implantation for optical wave-guides". Semiconductor Science and Technology 5, n.º 11 (1 de noviembre de 1990): 1146. http://dx.doi.org/10.1088/0268-1242/5/11/515.
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Dai, H., S. Janz, R. Normandin y F. Chatenoud. "InGaAs/GaAs single quantum well lasers with monolithically integrated multilayer wave guides for surface-emitted sum-frequency generation". Canadian Journal of Physics 70, n.º 10-11 (1 de octubre de 1992): 921–27. http://dx.doi.org/10.1139/p92-146.
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We report on strained layer InGaAs/GaAs single quantum well (SQW) lasers with monolithically integrated nonlinear wave guides for surface-emitting sum-frequency generation. Broad-area, ridge wave-guide and segmented cavity lasers with uncoated facets were processed from a molecular beam epitaxy grown AlxGa1 − xAs multilayer embedded with an InGaAs SQW separate cofinement heterostructure and tested at room temperature. Broad-area threshold current density of 87.5 A cm−2 was obtained for a cavity length of 3.3 mm and ridge lasers had a minimum threshold current of ~8 mA. The differential internal quantum efficiency, wave-guide loss, and lasing wavelength variation with cavity length were investigated. The sum-frequency generation (SFG) was studied in an active/passive segmented cavity device by coupling 1.06 μm light into the cavity as the transverse magnetic guided wave to interact with the transverse electric SQW laser mode. The measured conversion efficiency in terms of the nonlinear cross section An1 is about 2 × 10−7 W−1, which agrees well with the calculated value. Applications of the integrated devices as WDM demultiplexers and spatially addressable coherent detectors were demonstrated.
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Zanger, Benjamin, Christian B. Mendl, Martin Schulz y Martin Schreiber. "Quantum Algorithms for Solving Ordinary Differential Equations via Classical Integration Methods". Quantum 5 (13 de julio de 2021): 502. http://dx.doi.org/10.22331/q-2021-07-13-502.
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Identifying computational tasks suitable for (future) quantum computers is an active field of research. Here we explore utilizing quantum computers for the purpose of solving differential equations. We consider two approaches: (i) basis encoding and fixed-point arithmetic on a digital quantum computer, and (ii) representing and solving high-order Runge-Kutta methods as optimization problems on quantum annealers. As realizations applied to two-dimensional linear ordinary differential equations, we devise and simulate corresponding digital quantum circuits, and implement and run a 6th order Gauss-Legendre collocation method on a D-Wave 2000Q system, showing good agreement with the reference solution. We find that the quantum annealing approach exhibits the largest potential for high-order implicit integration methods. As promising future scenario, the digital arithmetic method could be employed as an "oracle" within quantum search algorithms for inverse problems.
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Lenkiewicz, Kacper y Joanna Wiśniewska. "The D-Wave quantum computer – advantages and disadvantages of moving away from the circuit model". Computer Science and Mathematical Modelling, n.º 11-12/2020 (30 de junio de 2021): 23–32. http://dx.doi.org/10.5604/01.3001.0015.2734.
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The paper is based on a thesis with the same title. The purpose of this thesis is to analyse D-Wave devices using quantum effects. The research focuses on demonstrating the advantages and disadvantages of a company moving away from the circuit model in its computers. The subject of the research is the used adiabatic model of quantum computing based on the mechanism of quantum annealing. The research is based on publicly available, comprehensive documentation of D-Wave Systems. On the basis of scientific papers, conferences and information contained in websites, controversies, disadvantages and advantages of the solutions adopted have been described.
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Crippa, Luca, Francesco Tacchino, Mario Chizzini, Antonello Aita, Michele Grossi, Alessandro Chiesa, Paolo Santini, Ivano Tavernelli y Stefano Carretta. "Simulating Static and Dynamic Properties of Magnetic Molecules with Prototype Quantum Computers". Magnetochemistry 7, n.º 8 (12 de agosto de 2021): 117. http://dx.doi.org/10.3390/magnetochemistry7080117.
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Magnetic molecules are prototypical systems to investigate peculiar quantum mechanical phenomena. As such, simulating their static and dynamical behavior is intrinsically difficult for a classical computer, due to the exponential increase of required resources with the system size. Quantum computers solve this issue by providing an inherently quantum platform, suited to describe these magnetic systems. Here, we show that both the ground state properties and the spin dynamics of magnetic molecules can be simulated on prototype quantum computers, based on superconducting qubits. In particular, we study small-size anti-ferromagnetic spin chains and rings, which are ideal test-beds for these pioneering devices. We use the variational quantum eigensolver algorithm to determine the ground state wave-function with targeted ansatzes fulfilling the spin symmetries of the investigated models. The coherent spin dynamics are simulated by computing dynamical correlation functions, an essential ingredient to extract many experimentally accessible properties, such as the inelastic neutron cross-section.
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Nembrini, Riccardo, Maurizio Ferrari Dacrema y Paolo Cremonesi. "Feature Selection for Recommender Systems with Quantum Computing". Entropy 23, n.º 8 (28 de julio de 2021): 970. http://dx.doi.org/10.3390/e23080970.
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The promise of quantum computing to open new unexplored possibilities in several scientific fields has been long discussed, but until recently the lack of a functional quantum computer has confined this discussion mostly to theoretical algorithmic papers. It was only in the last few years that small but functional quantum computers have become available to the broader research community. One paradigm in particular,quantum annealing, can be used to sample optimal solutions for a number of NP-hard optimization problems represented with classical operations research tools, providing an easy access to the potential of this emerging technology. One of the tasks that most naturally fits in this mathematical formulation is feature selection. In this paper, we investigate how to design a hybrid feature selection algorithm for recommender systems that leverages the domain knowledge and behavior hidden in the user interactions data. We represent the feature selection as an optimization problem and solve it on a real quantum computer, provided by D-Wave. The results indicate that the proposed approach is effective in selecting a limited set of important features and that quantum computers are becoming powerful enough to enter the wider realm of applied science.
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Bender, Carl M., Maarten DeKieviet y S. P. Klevansky. "PT quantum mechanics". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, n.º 1989 (28 de abril de 2013): 20120523. http://dx.doi.org/10.1098/rsta.2012.0523.
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-symmetric quantum mechanics (PTQM) has become a hot area of research and investigation. Since its beginnings in 1998, there have been over 1000 published papers and more than 15 international conferences entirely devoted to this research topic. Originally, PTQM was studied at a highly mathematical level and the techniques of complex variables, asymptotics, differential equations and perturbation theory were used to understand the subtleties associated with the analytic continuation of eigenvalue problems. However, as experiments on -symmetric physical systems have been performed, a simple and beautiful physical picture has emerged, and a -symmetric system can be understood as one that has a balanced loss and gain. Furthermore, the phase transition can now be understood intuitively without resorting to sophisticated mathe- matics. Research on PTQM is following two different paths: at a fundamental level, physicists are attempting to understand the underlying mathematical structure of these theories with the long-range objective of applying the techniques of PTQM to understanding some of the outstanding problems in physics today, such as the nature of the Higgs particle, the properties of dark matter, the matter–antimatter asymmetry in the universe, neutrino oscillations and the cosmological constant; at an applied level, new kinds of -synthetic materials are being developed, and the phase transition is being observed in many physical contexts, such as lasers, optical wave guides, microwave cavities, superconducting wires and electronic circuits. The purpose of this Theme Issue is to acquaint the reader with the latest developments in PTQM. The articles in this volume are written in the style of mini-reviews and address diverse areas of the emerging and exciting new area of -symmetric quantum mechanics.
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Deymier, Runge, Hasan y Calderin. "Exponentially Complex “Classically Entangled” States in Arrays of One-Dimensional Nonlinear Elastic Waveguides". Materials 12, n.º 21 (29 de octubre de 2019): 3553. http://dx.doi.org/10.3390/ma12213553.
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We demonstrate theoretically, using multiple-time-scale perturbation theory, the existence of nonseparable superpositions of elastic waves in an externally driven elastic system composed of three one-dimensional elastic wave guides coupled via nonlinear forces. The nonseparable states span a Hilbert space with exponential complexity. The amplitudes appearing in the nonseparable superposition of elastic states are complex quantities dependent on the frequency of the external driver. By tuning these complex amplitudes, we can navigate the state’s Hilbert space. This nonlinear elastic system is analogous to a two-partite two-level quantum system.
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Süsstrunk, Roman y Sebastian D. Huber. "Observation of phononic helical edge states in a mechanical topological insulator". Science 349, n.º 6243 (2 de julio de 2015): 47–50. http://dx.doi.org/10.1126/science.aab0239.
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A topological insulator, as originally proposed for electrons governed by quantum mechanics, is characterized by a dichotomy between the interior and the edge of a finite system: The bulk has an energy gap, and the edges sustain excitations traversing this gap. However, it has remained an open question whether the same physics can be observed for systems obeying Newton’s equations of motion. We conducted experiments to characterize the collective behavior of mechanical oscillators exhibiting the phenomenology of the quantum spin Hall effect. The phononic edge modes are shown to be helical, and we demonstrate their topological protection via the stability of the edge states against imperfections. Our results may enable the design of topological acoustic metamaterials that can capitalize on the stability of the surface phonons as reliable wave guides.
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Chatenoud, F., S. Janz, R. Normandin, H. Dai y J. P. McCaffrey. "AlGaAs/InGaAs/GaAs optoelectronic structures on (111)B GaAs". Canadian Journal of Physics 70, n.º 10-11 (1 de octubre de 1992): 1082–85. http://dx.doi.org/10.1139/p92-174.
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Epitaxial growth and the crystal-orientation specific optical properties of InGaAs quantum wells and AlGaAs surface-emitting harmonic generation wave-guides on (111) substrates are discussed. The samples were grown by molecular beam epitaxy on misoriented (111)B GaAs substrates. Low As4 overpressure and a very high substrate temperature lead to excellent surface morphology for both types of structures, making their growth compatible for later monolithic integration. InGaAs quantum wells are shown to be strongly affected by the strained-induced electric field. We observe an important increase, with In content, of the resultant redshift between (111) and (100) layers; a luminescence redshift as large as 55 meV for an 18% In well is measured. We also demonstrate for the first time surface emission harmonic generation from an all-AlGaAs second harmonic generation wave-guide pumped with 1.06 μm transverse electric (TE) polarized light; as predicted theoretically, the emitted light is uniform along the guide, and as intense as on a (100) crystal for TE–TM (transverse magnetic) interaction.
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Towler, M. D., N. J. Russell y Antony Valentini. "Time scales for dynamical relaxation to the Born rule". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, n.º 2140 (30 de noviembre de 2011): 990–1013. http://dx.doi.org/10.1098/rspa.2011.0598.
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We illustrate through explicit numerical calculations how the Born rule probability densities of non-relativistic quantum mechanics emerge naturally from the particle dynamics of de Broglie–Bohm pilot-wave theory. The time evolution of a particle distribution initially not equal to the absolute square of the wave function is calculated for a particle in a two-dimensional infinite potential square well. Under the de Broglie–Bohm ontology, the box contains an objectively existing ‘pilot wave’ which guides the electron trajectory, and this is represented mathematically by a Schrödinger wave function composed of a finite out-of-phase superposition of M energy eigenstates (with M ranging from 4 to 64). The electron density distributions are found to evolve naturally into the Born rule ones and stay there; in analogy with the classical case this represents a decay to ‘quantum equilibrium’. The proximity to equilibrium is characterized by the coarse-grained subquantum H -function which is found to decrease roughly exponentially towards zero over the course of time. The time scale τ for this relaxation is calculated for various values of M and the coarse-graining length ε . Its dependence on M is found to disagree with an earlier theoretical prediction. A power law, τ ∝ M −1 , is found to be fairly robust for all coarse-graining lengths and, although a weak dependence of τ on ε is observed, it does not appear to follow any straightforward scaling. A theoretical analysis is presented to explain these results. This improvement in our understanding of time scales for relaxation to quantum equilibrium is likely to be of use in the development of models of relaxation in the early Universe, with a view to constraining possible violations of the Born rule in inflationary cosmology.
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Su, Yuan, Hsin-Yuan Huang y Earl T. Campbell. "Nearly tight Trotterization of interacting electrons". Quantum 5 (5 de julio de 2021): 495. http://dx.doi.org/10.22331/q-2021-07-05-495.
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We consider simulating quantum systems on digital quantum computers. We show that the performance of quantum simulation can be improved by simultaneously exploiting commutativity of the target Hamiltonian, sparsity of interactions, and prior knowledge of the initial state. We achieve this using Trotterization for a class of interacting electrons that encompasses various physical systems, including the plane-wave-basis electronic structure and the Fermi-Hubbard model. We estimate the simulation error by taking the transition amplitude of nested commutators of the Hamiltonian terms within the η-electron manifold. We develop multiple techniques for bounding the transition amplitude and expectation of general fermionic operators, which may be of independent interest. We show that it suffices to use (n5/3η2/3+n4/3η2/3)no(1) gates to simulate electronic structure in the plane-wave basis with n spin orbitals and η electrons, improving the best previous result in second quantization up to a negligible factor while outperforming the first-quantized simulation when n=η2−o(1). We also obtain an improvement for simulating the Fermi-Hubbard model. We construct concrete examples for which our bounds are almost saturated, giving a nearly tight Trotterization of interacting electrons.
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Flambaum, V. V. "Time Dynamics in Chaotic Many-body Systems: Can Chaos Destroy a Quantum Computer?" Australian Journal of Physics 53, n.º 4 (2000): 489. http://dx.doi.org/10.1071/ph99091.
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Highly excited many-particle states in quantum systems (nuclei, atoms, quantum dots, spin systems, quantum computers) can be ‘chaotic’ superpositions of mean-field basis states (Slater determinants, products of spin or qubit states). This is a result of the very high energy level density of many-body states which can be easily mixed by a residual interaction between particles. We consider the time dynamics of wave functions and increase of entropy in such chaotic systems. As an example, we present the time evolution in a closed quantum computer. A time scale for the entropy S(t) increase is t c ~τ 0 /(n log 2 n), where τ 0 is the qubit ‘lifetime’, n is the number of qubits, S(0) = 0 and S(t c )=1. At t _ t c the entropy is small: S ~nt 2 J 2 log 2 (1/t 2 J2 ), where J is the inter-qubit interaction strength. At t > t c the number of ‘wrong’ states increases exponentially as 2 S(t) . Therefore, t c may be interpreted as a maximal time for operation of a quantum computer. At t >>t c the system entropy approaches that for chaotic eigenstates.
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Yung, Man-Hong, Xun Gao y Joonsuk Huh. "Universal bound on sampling bosons in linear optics and its computational implications". National Science Review 6, n.º 4 (9 de abril de 2019): 719–29. http://dx.doi.org/10.1093/nsr/nwz048.
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ABSTRACT In linear optics, photons are scattered in a network through passive optical elements including beam splitters and phase shifters, leading to many intriguing applications in physics, such as Mach–Zehnder interferometry, the Hong–Ou–Mandel effect, and tests of fundamental quantum mechanics. Here we present the fundamental limit in the transition amplitudes of bosons, applicable to all physical linear optical networks. Apart from boson sampling, this transition bound results in many other interesting applications, including behaviors of Bose–Einstein condensates (BEC) in optical networks, counterparts of Hong–Ou–Mandel effects for multiple photons, and approximating permanents of matrices. In addition, this general bound implies the existence of a polynomial-time randomized algorithm for estimating the transition amplitudes of bosons, which represents a solution to an open problem raised by Aaronson and Hance (Quantum Inf Comput 2012; 14: 541–59). Consequently, this bound implies that computational decision problems encoded in linear optics, prepared and detected in the Fock basis, can be solved efficiently by classical computers within additive errors. Furthermore, our result also leads to a classical sampling algorithm that can be applied to calculate the many-body wave functions and the S-matrix of bosonic particles.
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Tiurin, Sergey. "A “BILLIARDS” SIMULATION OF AN UNIVERSAL LOGIC MODULES BASED ON THE FREDKIN GATES FOR THE QUANT-UTING". Applied Mathematics and Control Sciences, n.º 2 (30 de junio de 2020): 55–72. http://dx.doi.org/10.15593/2499-9873/2020.2.04.
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In the wave of the green computing trend, research has recently intensified on the so-called adiabatic logic, reversible computing, which is supposed to be the basis of quantum computers and bring to a new level of computing power, combined with low power consumption. The basis of this logic is special reversible gates, for example, Fredkin’s gates. Reversibility is a one-to-one correspondence (bijection) between the inputs and outputs of circuits, which means, on the one hand, the possibility of total control of the results of calculations, and on the other hand, the possibility of returning the obtained "energy" quanta for the perform calculations to their source. This approach can significantly reduce the power consumption of computers, as well as increase the reliability of calculations. There are a lot of publications on this topic, however, the development of universal logic modules on such a basis has not been fully considered. The aim of the study is the development and modeling of universal logic modules based on the Fredkin element. In this case, the methods of logical synthesis of a reversible scheme based on a binary Fredkin element, modeling and analysis of billiard calculations are used. The article presents the proposed schemes of the decoder and multiplexer based on the Fredkin element, the "billiard" simulation. The practical significance of the study lies in the fact that the obtained universal logic modules can be used in the synthesis of binary reversible circuits, for example, FPGAs. The performed simulation can be used as examples in practical exercises in the discrete mathematics, mathematical logic, mathematical modeling, and circuitry disciplines.
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OCKMAN, NATHAN, WUBAO WANG y R. R. ALFANO. "APPLICATIONS OF ULTRAFAST LASER SPECTROSCOPY TO THE STUDY OF SEMICONDUCTOR PHYSICS". International Journal of Modern Physics B 05, n.º 20 (diciembre de 1991): 3165–234. http://dx.doi.org/10.1142/s0217979291001255.
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This article reviews the application of some of the principal methods of picosecond and femtosecond laser spectroscopy to the investigation of the dynamics of carriers, phonons and surface structure in semiconductors. The measurement of the temporal evolution of photoinduced luminescence, absorption, reflection and scattering in semiconductors makes it possible to obtain the lifetimes of photogenerated electrons, holes, excitons and phonons in both the bulk and quantum wells and superlattice structures. The information produced by these studies is necessary for the basic understanding of the underlying physics of semiconductors. In addition, the parameters obtained from these studies are needed for evaluating ultrafast transport, switching, photoconductive response and imaging in semiconductor materials, which will determine their limitations for use in high-speed and high-frequency devices and computers. For measuring time resolved luminescence, the principal techniques used, namely, the streak camera, the optical Kerr gate and the up-conversion gate are thoroughly discussed. Several pump and probe methods are described for the determination of time resolved absorption, reflection and Raman scattering. For absorption measurements where the probe wavelength differs from the pump, the former is generated in nonlinear media by means of stimulated Raman scattering and the supercontinuum for the UV and visible regions and by parametric and difference frequency generation for the near- and mid-IR. Nonlinear optics techniques considered are degenerate and nondegenerate four-wave mixing and transient grattings among which photon echoes yield the momentum relaxation of hot electrons. Coherent anti-Stokes Raman scattering (CARS) and phase conjugate Raman scattering (PC) are described to determine phonon dephasing times and the nonlinear susceptibility, χ3.
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Mielczarek, Jakub. "Prelude to Simulations of Loop Quantum Gravity on Adiabatic Quantum Computers". Frontiers in Astronomy and Space Sciences 8 (10 de junio de 2021). http://dx.doi.org/10.3389/fspas.2021.571282.
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The article addresses the possibility of implementing spin network states, used in the loop quantum gravity approach to Planck scale physics on an adiabatic quantum computer. The discussion focuses on applying currently available technologies and analyzes a concrete example of a D-Wave machine. It is introduced a class of simple spin network states which can be implemented on the Chimera graph architecture of the D-Wave quantum processor. However, extension beyond the currently available quantum processor topologies is required to simulate more sophisticated spin network states. This may inspire new generations of adiabatic quantum computers. A possibility of simulating loop quantum gravity is discussed, and a method of solving a graph non-changing scalar (Hamiltonian) constraint with the use of adiabatic quantum computations is proposed. The presented results establish a basis for the future simulations of Planck scale physics, specifically quantum cosmological configurations, on quantum annealers.
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Impens, François, Romain Duboscq y David Guéry-Odelin. "Quantum Control beyond the Adiabatic Regime in 2D Curved Matter-Wave Guides". Physical Review Letters 124, n.º 25 (22 de junio de 2020). http://dx.doi.org/10.1103/physrevlett.124.250403.
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Teplukhin, Alexander, Brian K. Kendrick, Sergei Tretiak y Pavel A. Dub. "Electronic structure with direct diagonalization on a D-wave quantum annealer". Scientific Reports 10, n.º 1 (27 de noviembre de 2020). http://dx.doi.org/10.1038/s41598-020-77315-4.
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AbstractQuantum chemistry is regarded to be one of the first disciplines that will be revolutionized by quantum computing. Although universal quantum computers of practical scale may be years away, various approaches are currently being pursued to solve quantum chemistry problems on near-term gate-based quantum computers and quantum annealers by developing the appropriate algorithm and software base. This work implements the general Quantum Annealer Eigensolver (QAE) algorithm to solve the molecular electronic Hamiltonian eigenvalue-eigenvector problem on a D-Wave 2000Q quantum annealer. The approach is based on the matrix formulation, efficiently uses qubit resources based on a power-of-two encoding scheme and is hardware-dominant relying on only one classically optimized parameter. We demonstrate the use of D-Wave hardware for obtaining ground and excited electronic states across a variety of small molecular systems. The approach can be adapted for use by a vast majority of electronic structure methods currently implemented in conventional quantum-chemical packages. The results of this work will encourage further development of software such as qbsolv which has promising applications in emerging quantum information processing hardware and has expectation to address large and complex optimization problems intractable for classical computers.
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Bera, Rajendra K. "The Essence of Quantum Computing". Advanced Computing and Communications, 10 de marzo de 2018. http://dx.doi.org/10.34048/2018.1.f1.
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It now appears that quantum computers are poised to enter the world of computing and establish its dominance, especially, in the cloud. Turing machines (classical computers) tied to the laws of classical physics will not vanish from our lives but begin to play a subordinate role to quantum computers tied to the enigmatic laws of quantum physics that deal with such non-intuitive phenomena as superposition, entanglement, collapse of the wave function, and teleportation, all occurring in Hilbert space. The aim of this 3-part paper is to introduce the readers to a core set of quantum algorithms based on the postulates of quantum mechanics, and reveal the amazing power of quantum computing.
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Klco, Natalie y Martin J. Savage. "Minimally entangled state preparation of localized wave functions on quantum computers". Physical Review A 102, n.º 1 (17 de julio de 2020). http://dx.doi.org/10.1103/physreva.102.012612.
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Teplukhin, Alexander, Brian K. Kendrick, Susan M. Mniszewski, Yu Zhang, Ashutosh Kumar, Christian F. A. Negre, Petr M. Anisimov, Sergei Tretiak y Pavel A. Dub. "Computing molecular excited states on a D-Wave quantum annealer". Scientific Reports 11, n.º 1 (22 de septiembre de 2021). http://dx.doi.org/10.1038/s41598-021-98331-y.
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AbstractThe possibility of using quantum computers for electronic structure calculations has opened up a promising avenue for computational chemistry. Towards this direction, numerous algorithmic advances have been made in the last five years. The potential of quantum annealers, which are the prototypes of adiabatic quantum computers, is yet to be fully explored. In this work, we demonstrate the use of a D-Wave quantum annealer for the calculation of excited electronic states of molecular systems. These simulations play an important role in a number of areas, such as photovoltaics, semiconductor technology and nanoscience. The excited states are treated using two methods, time-dependent Hartree–Fock (TDHF) and time-dependent density-functional theory (TDDFT), both within a commonly used Tamm–Dancoff approximation (TDA). The resulting TDA eigenvalue equations are solved on a D-Wave quantum annealer using the Quantum Annealer Eigensolver (QAE), developed previously. The method is shown to reproduce a typical basis set convergence on the example $$\hbox {H}_2$$ H 2 molecule and is also applied to several other molecular species. Characteristic properties such as transition dipole moments and oscillator strengths are computed as well. Three potential energy profiles for excited states are computed for $$\hbox {NH}_3$$ NH 3 as a function of the molecular geometry. Similar to previous studies, the accuracy of the method is dependent on the accuracy of the intermediate meta-heuristic software called qbsolv.
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Bera, Rajendra K. "The Essence of Quantum Computing". Advanced Computing and Communications, 10 de septiembre de 2018. http://dx.doi.org/10.34048/2018.3.f3.
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In Part I we laid the foundation on which quantum algorithms are built. In part II we harnessed such exotic aspects of quantum mechanics as superposition, entanglement and collapse of quantum states to show how powerful quantum algorithms can be constructed for efficient computation. In Part III (the concluding part) we discuss two aspects of quantum computation: (1) the problem of correcting errors that inevitably plague physical quantum computers during computations, by algorithmic means; and (2) a possible underlying mechanism for the collapse of the wave function during measurement.
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Nakano, Aiichiro, Rajiv K. Kalia y Priya Vashishta. "Quantum Dynamical Simulation of Many Electron-Phonon Coupled Systems on Parallel Computers". MRS Proceedings 291 (1 de enero de 1992). http://dx.doi.org/10.1557/proc-291-73.
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ABSTRACTA quantum dynamical simulation method is developed to investigate coupled many electron-phonon systems. Both electron and phonon wave functions are numerically propagated in time. The method is applied to the study of resonant tunneling of an electron through double quantum dots. Phonon-induced electron localization is observed. The space- splitting Schrödinger solver and dynamical-simulated-annealing Poisson solver are implemented on an 8,192-node MP-1 computer from MasPar.
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Vashishta, Priya, Rajiv K. Kalia y Jin Yu. "Classical and Quantum Simulations for Large Systems on Parallel Computers". MRS Proceedings 291 (1 de enero de 1992). http://dx.doi.org/10.1557/proc-291-3.
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ABSTRACTMolecular dynamics (MD) method is used to investigate structural transformation and the loss of intermediate range order in SiO2 glass at very large positive pressures and the modification of SiO2 glass network at very large negative pressures. The nature of molecular vibrations in solid C60 has been studied with tight binding molecular dynamics (TBMD) method. Implementations of simulation algorithms on parallel computers are also discussed.In a-SiO2 at high pressures, the height of the first sharp diffraction peak in S(q) is considerably diminished and its position shifts to larger wave vectors. At twice the normal density, Si-O bond length increases, Si-O coordination changes from 4 to 6, and O-Si-O band-angle changes from 109° to 90°. This is clearly a tetrahedral to octahedral transformation, which is observed recently by Meade, Hemley, and Mao in their diffraction experiments using synchrotron radiation.MD simulations of porous silica are carried out in the density range 2.2 - 0.1 g/cm3 Internal surface area, pore surface-to-volume ratio, gyration radius, and fractal dimension are studied as a function of density. Simulations are in good agreement with the experimental results obtained by x-ray scattering. The results reveal a crossover of the structural correlations between short- to intermediate-range (< 8 Å) and fractal- to large-scale-regime (10 ~ 100 Å).Dispersion and density of states (DOS) of inter- and intra-molecular phonons are calculated for orientationally ordered and disordered solid C60 using the TBMD method. Inter-molecular phonon DOS extends up to 7.6 meV and shows libron peaks at 2.4 meV and 3.7 meV in the orientationally ordered phase. Orientational disorder softens libron modes. Intra-molecular phonons below 70 meV also show significant dispersion. Our results are in good agreement with the recent inelastic neutron scattering experiments.MD is a numerical approach which involves the solution of Newton's equations for particles in the system. The multiple-time-step (MTS) approach reduces this computation significantly by exploiting the different time scales for short-range and intermediate-range interactions. Using the linked-list scheme, parallel algorithms are designed to implement on the in-house 8-node iPSC/860, a MIMD (multiple instruction multiple data) machine. Our group has also developed a quantum dynamical simulation scheme for Computational Nanoelectronics based on the quantum molecular dynamics (QMD) method. The QMD algorithm has been implemented on the in-house 8,192-node MasPar, a SIMD (single instruction multiple data) architecture.
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"Hardware and quantum mechanical calculations". Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences 341, n.º 1661 (16 de noviembre de 1992): 361–71. http://dx.doi.org/10.1098/rsta.1992.0108.
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The remarkable progress in the architecture, speed and capacity of computer hardware continues to drive the development of quantum mechanical methods, thus allowing calculations on increasingly complex systems. Using high-end computers, accurate quantum mechanical all-electron studies are now possible for solids such as transition metal compounds containing about fifty atoms per unit cell. Pseudo-potential plane-wave methods are being applied to unit cells with 400 silicon atoms, and organic molecules consisting of over 100 atoms have become tractable using ab initio methods. Smaller, yet still useful calculations can be carried out on workstations. The combination of graphics workstations and high-performance supercomputers, integrated in tightly coupled heterogeneous networks, has allowed the design of software systems with unprecedented convenience and visualization capabilities. Despite this progress, however, there is still an urgent need for new quantum mechanical methods which converge systematically to the exact solution of Schrodinger’s equation while maintaining a reasonable scaling of the computational effort with the system size.
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Vert, Daniel, Renaud Sirdey y Stéphane Louise. "Benchmarking Quantum Annealing Against “Hard” Instances of the Bipartite Matching Problem". SN Computer Science 2, n.º 2 (20 de febrero de 2021). http://dx.doi.org/10.1007/s42979-021-00483-1.
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AbstractThis paper experimentally investigates the behavior of analog quantum computers as commercialized by D-Wave when confronted to instances of the maximum cardinality matching problem which is specifically designed to be hard to solve by means of simulated annealing. We benchmark a D-Wave “Washington” (2X) with 1098 operational qubits on various sizes of such instances and observe that for all but the most trivially small of these it fails to obtain an optimal solution. Thus, our results suggest that quantum annealing, at least as implemented in a D-Wave device, falls in the same pitfalls as simulated annealing and hence provides additional evidences suggesting that there exist polynomial-time problems that such a machine cannot solve efficiently to optimality. Additionally, we investigate the extent to which the qubits interconnection topologies explains these latter experimental results. In particular, we provide evidences that the sparsity of these topologies which, as such, lead to QUBO problems of artificially inflated sizes can partly explain the aforementioned disappointing observations. Therefore, this paper hints that denser interconnection topologies are necessary to unleash the potential of the quantum annealing approach.
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Park, Jae Whan, Jinwon Lee y Han Woong Yeom. "Zoology of domain walls in quasi-2D correlated charge density wave of 1T-TaS2". npj Quantum Materials 6, n.º 1 (22 de marzo de 2021). http://dx.doi.org/10.1038/s41535-021-00330-9.
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AbstractDomain walls in correlated charge density wave compounds such as 1T-TaS2 can have distinct localized states which govern physical properties and functionalities of emerging quantum phases. However, detailed atomic and electronic structures of domain walls have largely been elusive. We identify using scanning tunneling microscope and density functional theory calculations the atomic and electronic structures for a plethora of discommensuration domain walls in 1T-TaS2 quenched metastably with nanoscale domain wall networks. The domain walls exhibit various in-gap states within the Mott gap but metallic states appear in only particular types of domain walls. A systematic understanding of the domain-wall electronic property requests not only the electron counting but also including various intertwined interactions such as structural relaxation, electron correlation, and charge transfer. This work guides the domain wall engineering of the functionality in correlated van der Waals materials.
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Giovinazzo, J., T. Roger, B. Blank, D. Rudolph, B. A. Brown, H. Alvarez-Pol, A. Arokia Raj et al. "4D-imaging of drip-line radioactivity by detecting proton emission from 54mNi pictured with ACTAR TPC". Nature Communications 12, n.º 1 (10 de agosto de 2021). http://dx.doi.org/10.1038/s41467-021-24920-0.
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AbstractProton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.
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Bylaska, Eric J., Duo Song, Nicholas P. Bauman, Karol Kowalski, Daniel Claudino y Travis S. Humble. "Quantum Solvers for Plane-Wave Hamiltonians: Abridging Virtual Spaces Through the Optimization of Pairwise Correlations". Frontiers in Chemistry 9 (18 de marzo de 2021). http://dx.doi.org/10.3389/fchem.2021.603019.
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For many-body methods such as MCSCF and CASSCF, in which the number of one-electron orbitals is optimized and independent of the basis set used, there are no problems with using plane-wave basis sets. However, for methods currently used in quantum computing such as select configuration interaction (CI) and coupled cluster (CC) methods, it is necessary to have a virtual space that is able to capture a significant amount of electron-electron correlation in the system. The virtual orbitals in a pseudopotential plane-wave Hartree–Fock calculation, because of Coulomb repulsion, are often scattering states that interact very weakly with the filled orbitals. As a result, very little correlation energy is captured from them. The use of virtual spaces derived from the one-electron operators has also been tried, and while some correlations are captured, the amount is quite low. To overcome these limitations, we have been developing new classes of algorithms to define virtual spaces by optimizing orbitals from small pairwise CI Hamiltonians, which we term as correlation optimized virtual orbitals with the abbreviation COVOs. With these procedures, we have been able to derive virtual spaces, containing only a few orbitals, which are able to capture a significant amount of correlation. The focus in this manuscript is on using these derived basis sets to target full CI (FCI) quality results for H2 on near-term quantum computers. However, the initial results for this approach were promising. We were able to obtain good agreement with FCI/cc-pVTZ results for this system with just 4 virtual orbitals, using both FCI and quantum simulations. The quality of the results using COVOs suggests that it may be possible to use them in other many-body approaches, including coupled cluster and Møller–Plesset perturbation theories, and open up the door to many-body calculations for pseudopotential plane-wave basis set methods.
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Sato, Takehito, Masayuki Ohzeki y Kazuyuki Tanaka. "Assessment of image generation by quantum annealer". Scientific Reports 11, n.º 1 (29 de junio de 2021). http://dx.doi.org/10.1038/s41598-021-92295-9.
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AbstractQuantum annealing was originally proposed as an approach for solving combinatorial optimization problems using quantum effects. D-Wave Systems has released a production model of quantum annealing hardware. However, the inherent noise and various environmental factors in the hardware hamper the determination of optimal solutions. In addition, the freezing effect in regions with weak quantum fluctuations generates outputs approximately following a Gibbs–Boltzmann distribution at an extremely low temperature. Thus, a quantum annealer may also serve as a fast sampler for the Ising spin-glass problem, and several studies have investigated Boltzmann machine learning using a quantum annealer. Previous developments have focused on comparing the performance in the standard distance of the resulting distributions between conventional methods in classical computers and sampling by a quantum annealer. In this study, we focused on the performance of a quantum annealer as a generative model from a different aspect. To evaluate its performance, we prepared a discriminator given by a neural network trained on an a priori dataset. The evaluation results show a higher performance of quantum annealer compared with the classical approach for Boltzmann machine learning in training of the generative model. However the generation of the data suffers from the remanent quantum fluctuation in the quantum annealer. The quality of the generated images from the quantum annealer gets worse than the ideal case of the quantum annealing and the classical Monte-Carlo sampling.
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Chen, Hui, Hongkuan Zhang, Qian Wu, Yu Huang, Huy Nguyen, Emil Prodan, Xiaoming Zhou y Guoliang Huang. "Creating synthetic spaces for higher-order topological sound transport". Nature Communications 12, n.º 1 (19 de agosto de 2021). http://dx.doi.org/10.1038/s41467-021-25305-z.
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AbstractModern technological advances allow for the study of systems with additional synthetic dimensions. Higher-order topological insulators in topological states of matters have been pursued in lower physical dimensions by exploiting synthetic dimensions with phase transitions. While synthetic dimensions can be rendered in the photonics and cold atomic gases, little to no work has been succeeded in acoustics because acoustic wave-guides cannot be weakly coupled in a continuous fashion. Here, we formulate the theoretical principles and manufacture acoustic crystals composed of arrays of acoustic cavities strongly coupled through modulated channels to evidence one-dimensional (1D) and two-dimensional (2D) dynamic topological pumpings. In particular, the higher-order topological edge-bulk-edge and corner-bulk-corner transport are physically illustrated in finite-sized acoustic structures. We delineate the generated 2D and four-dimensional (4D) quantum Hall effects by calculating first and second Chern numbers and physically demonstrate robustness against the geometrical imperfections. Synthetic dimensions could provide a powerful way for acoustic topological wave steering and open up a platform to explore any continuous orbit in higher-order topological matter in dimensions four and higher.
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Camacho, Miguel, Brian Edwards y Nader Engheta. "A single inverse-designed photonic structure that performs parallel computing". Nature Communications 12, n.º 1 (5 de marzo de 2021). http://dx.doi.org/10.1038/s41467-021-21664-9.
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AbstractIn the search for improved computational capabilities, conventional microelectronic computers are facing various problems arising from the miniaturization and concentration of active electronics. Therefore, researchers have explored wave systems, such as photonic or quantum devices, for solving mathematical problems at higher speeds and larger capacities. However, previous devices have not fully exploited the linearity of the wave equation, which as we show here, allows for the simultaneous parallel solution of several independent mathematical problems within the same device. Here we demonstrate that a transmissive cavity filled with a judiciously tailored dielectric distribution and embedded in a multi-frequency feedback loop can calculate the solutions of a number of mathematical problems simultaneously. We design, build, and test a computing structure at microwave frequencies that solves two independent integral equations with any two arbitrary inputs and also provide numerical results for the calculation of the inverse of four 5 x 5 matrices.
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Hu, Yingtao, Di Liang, Kunal Mukherjee, Youli Li, Chong Zhang, Geza Kurczveil, Xue Huang y Raymond G. Beausoleil. "III/V-on-Si MQW lasers by using a novel photonic integration method of regrowth on a bonding template". Light: Science & Applications 8, n.º 1 (9 de octubre de 2019). http://dx.doi.org/10.1038/s41377-019-0202-6.
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Abstract Silicon photonics is becoming a mainstream data-transmission solution for next-generation data centers, high-performance computers, and many emerging applications. The inefficiency of light emission in silicon still requires the integration of a III/V laser chip or optical gain materials onto a silicon substrate. A number of integration approaches, including flip-chip bonding, molecule or polymer wafer bonding, and monolithic III/V epitaxy, have been extensively explored in the past decade. Here, we demonstrate a novel photonic integration method of epitaxial regrowth of III/V on a III/V-on-SOI bonding template to realize heterogeneous lasers on silicon. This method decouples the correlated root causes, i.e., lattice, thermal, and domain mismatches, which are all responsible for a large number of detrimental dislocations in the heteroepitaxy process. The grown multi-quantum well vertical p–i–n diode laser structure shows a significantly low dislocation density of 9.5 × 104 cm−2, two orders of magnitude lower than the state-of-the-art conventional monolithic growth on Si. This low dislocation density would eliminate defect-induced laser lifetime concerns for practical applications. The fabricated lasers show room-temperature pulsed and continuous-wave lasing at 1.31 μm, with a minimal threshold current density of 813 A/cm2. This generic concept can be applied to other material systems to provide higher integration density, more functionalities and lower total cost for photonics as well as microelectronics, MEMS, and many other applications.
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Thanh, Le Trung. "LeTrungThanh Optical Biosensors Based on Multimode Interference and Microring Resonator Structures". VNU Journal of Science: Natural Sciences and Technology 34, n.º 1 (23 de marzo de 2018). http://dx.doi.org/10.25073/2588-1140/vnunst.4727.
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We review our recent work on optical biosensors based on microring resonators (MRR) integrated with 4x4 multimode interference (MMI) couplers for multichannel and highly sensitive chemical and biological sensors. The proposed sensor structure has advantages of compactness, high sensitivity compared with the reported sensing structures. By using the transfer matrix method (TMM) and numerical simulations, the designs of the sensor based on silicon waveguides are optimized and demonstrated in detail. We applied our structure to detect glucose and ethanol concentrations simultaneously. A high sensitivity of 9000 nm/RIU, detection limit of 2x10-4 for glucose sensing and sensitivity of 6000nm/RIU, detection limit of 1.3x10-5 for ethanol sensing are achieved.
Keywords
Biological sensors, chemical sensors, optical microring resonators, high sensitivity, multimode interference, transfer matrix method, beam propagation method (BPM), multichannel sensor
References
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