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Journal articles on the topic 'Quantum Nuclear Motion'

Author: Grafiati
Published: 6 September 2023

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1

Frank, Irmgard. "Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion." Hydrogen 4, no. 1 (2022): 11–21. http://dx.doi.org/10.3390/hydrogen4010002.

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Ab initio molecular dynamics combines a classical description of nuclear motion with a density-functional description of the electronic cloud. This approach nicely describes chemical reactions. A possible conclusion is that a quantum mechanical description of nuclear motion is not needed. Using Occam’s razor, this means that, being the simpler approach, classical nuclear motion is preferable. In this paper, it is claimed that nuclear motion is classical, and this hypothesis will be tested in comparison to methods with quantum mechanical nuclear motion. In particular, we apply ab initio molecular dynamics to two photoreactions involving hydrogen. Hydrogen, as the lightest element, is often assumed to show quantum mechanical tunneling. We will see that the classical picture is fully sufficient. The quantum mechanical view leads to phenomena that are difficult to understand, such as the entanglement of nuclear motion. In contrast, it is easy to understand the simple classical picture which assumes that nuclear motion is steady and uniform unless a force is acting. Of course, such a hypothesis must be verified for many systems and phenomena, and this paper is one more step in this direction.
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2

Wu, Xizhen, Zhuxia Li, J. A. Maruhn, W. Greiner, and Y. Zhuo. "Quantum Brownian motion and nuclear fission." Journal of Physics G: Nuclear Physics 14, no. 8 (1988): 1049–58. http://dx.doi.org/10.1088/0305-4616/14/8/008.

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3

McKenzie, Ross H., Christiaan Bekker, Bijyalaxmi Athokpam, and Sai G. Ramesh. "Effect of quantum nuclear motion on hydrogen bonding." Journal of Chemical Physics 140, no. 17 (2014): 174508. http://dx.doi.org/10.1063/1.4873352.

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4

Petek, H., H. Nagano, M. J. Weida, and S. Ogawa. "Quantum Control of Nuclear Motion at a Metal Surface†." Journal of Physical Chemistry A 104, no. 45 (2000): 10234–39. http://dx.doi.org/10.1021/jp001218a.

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5

Oi, Makito. "Semi-classical and anharmonic quantum models of nuclear wobbling motion." Physics Letters B 634, no. 1 (2006): 30–34. http://dx.doi.org/10.1016/j.physletb.2005.12.061.

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6

ROTTER, I. "THE INTERPLAY BETWEEN REGULAR AND CHAOTIC MOTION IN NUCLEI." Modern Physics Letters A 02, no. 04 (1987): 233–37. http://dx.doi.org/10.1142/s021773238700032x.

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The regular motion of nucleons in the low-lying nuclear states and the chaotic motion in the compound nuclei are shown to arise from the interplay of conservative and dissipative forces in the open quantum mechanical nuclear system. The regularity at low level density is caused by selforganization in a conservative field of force. At high level density, chaoticity appears since information on the environment is transferred into the system by means of dissipative forces.
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7

Håkansson, Pär. "Prediction of low-field nuclear singlet lifetimes with molecular dynamics and quantum-chemical property surface." Physical Chemistry Chemical Physics 19, no. 16 (2017): 10237–54. http://dx.doi.org/10.1039/c6cp08394c.

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8

Bonatsos, D., P. E. Georgoudis, D. Lenis, N. Minkov, and C. Quesne. "SUSYQM in nuclear structure: Bohr Hamiltonian with mass depending on the deformation." HNPS Proceedings 18 (November 23, 2019): 69. http://dx.doi.org/10.12681/hnps.2540.

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A well known problem of the Bohr Hamiltonian for the description of nuclear collective motion is that the nuclear moment of inertia increases with deformation too fast. We show that this can be avoided by allowing the nuclear mass to depend on the deformation. The resulting Hamiltonian is solved exactly, using techniques of Supersymmetric Quantum Mechanics
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9

BLOCKI, J. P., A. G. MAGNER, and I. S. YATSYSHYN. "GROSS-SHELL EFFECTS IN THE DISSIPATIVE NUCLEAR DYNAMICS." International Journal of Modern Physics E 21, no. 05 (2012): 1250034. http://dx.doi.org/10.1142/s0218301312500346.

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The order-to-chaos transition in the dynamics of the quantum gas of independent particles was studied within the nuclear model based on the time-dependent mean-field approach. The excitation of the quantum gas in the Woods–Saxon potential with a small diffuseness of its surface rippled according to the Legendre polynomials P2 and P3 are obtained for a slow and small amplitude collective motion. We found strong correlations between time-derivatives of the excitation energies (one-body friction coefficients) and shell-correction energies as functions of the particle number. Semiclassical estimates of the friction coefficients were obtained within the periodic orbit theory by using the uniform approximation.
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10

Abedi, Ali, Federica Agostini, and E. K. U. Gross. "Mixed quantum-classical dynamics from the exact decomposition of electron-nuclear motion." EPL (Europhysics Letters) 106, no. 3 (2014): 33001. http://dx.doi.org/10.1209/0295-5075/106/33001.

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11

Albert, Julian, Dustin Kaiser, and Volker Engel. "Communication: Adiabatic and non-adiabatic electron-nuclear motion: Quantum and classical dynamics." Journal of Chemical Physics 144, no. 17 (2016): 171103. http://dx.doi.org/10.1063/1.4948777.

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12

Kuzyakin, R. A., V. V. Sargsyan, G. G. Adamian, and N. V. Antonenko. "Large-amplitude nuclear motion formulated in terms of dissipation of quantum fluctuations." Physics of Particles and Nuclei 48, no. 1 (2017): 158–209. http://dx.doi.org/10.1134/s1063779617010130.

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13

Hauser, Andreas W., Alexander O. Mitrushchenkov, and María Pilar de Lara-Castells. "Quantum Nuclear Motion of Helium and Molecular Nitrogen Clusters in Carbon Nanotubes." Journal of Physical Chemistry C 121, no. 7 (2017): 3807–21. http://dx.doi.org/10.1021/acs.jpcc.6b12959.

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14

Light, Gregory L. "Quantum Mechanics by General Relativity." Applied Physics Research 11, no. 2 (2019): 1. http://dx.doi.org/10.5539/apr.v11n2p1.

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In the framework of General Relativity we explain the creation of all particles, ordinary and anti, in two chiral directions, with multiple generations, as well as electromagnetism and the strong nuclear force. Quantum mechanics is well-known to have its foundational problems revolving around the wave-particle duality, which actually has an exact solution, viz., a diagonal spacetime manifold that admits any particle of energy coupled with its wave of energy co-existing at the same spacetime (t + it, x + iy, y + iz, z + ix). I.e., a photon can travel along x = ct with its associated electromagnetic wave spinning from y to z in circular motion as (y = cos t, z = sin t) ≡ eit. The construct of diagonal manifold, seemingly artificial, is fundamental in differential topology as it leads to the Euler characteristic. That Nature is inherently of duality cannot have a more evident example than that of the complex number x + iy, where 1 implies a linear motion in R and i = eπ2 i implies a circular motion along S 1. That the quantum wave itself possesses energy can be argued simply as: wave = probability = frequency = energy by Planck’s formula. By assigning energy entirely to particle, quantum mechanics has missed an entire copy of the Universe (the wave universe treated as the quantum vacuum).
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15

Dzhunushaliev, Vladimir. "Toy Models of a Nonassociative Quantum Mechanics." Advances in High Energy Physics 2007 (2007): 1–10. http://dx.doi.org/10.1155/2007/12387.

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Toy models of a nonassociative quantum mechanics are presented. The Heisenberg equation of motion is modified using a nonassociative commutator. Possible physical applications of a nonassociative quantum mechanics are considered. The idea is discussed that a nonassociative algebra could be the operator language for the nonperturbative quantum theory. In such approach the nonperturbative quantum theory has observables and unobservables quantities.
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16

Li, Hong-Xing. "Unified theory of classic mechanics and quantum mechanics." Modern Physics Letters A 35, no. 38 (2020): 2030022. http://dx.doi.org/10.1142/s0217732320300220.

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In this paper, I review one of the most important and interesting parts of my new book “Fuzzy Systems to Quantum Mechanics” (see Ref. 1). Several conclusions in this part are worth introducing here. First of all, the motion of a mass point in classic mechanics has also waviness and the wave function of the motion of a mass point is composed of wave functions of countably infinite microscopic particles. Secondly, based on the waviness of the motion of a mass point we surely know the new conclusion described as the wave-mass-point dualism in classic mechanics. And thirdly, by using the closed relation between the wave-mass-point dualism in classic mechanics and the wave-particle dualism in quantum mechanics, unified theory of classic mechanics and quantum mechanics is naturally formed.
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17

Ciaglia, F. M., F. Di Cosmo, A. Ibort, G. Marmo, L. Schiavone, and A. Zampini. "Lagrangian description of Heisenberg and Landau–von Neumann equations of motion." Modern Physics Letters A 35, no. 19 (2020): 2050161. http://dx.doi.org/10.1142/s0217732320501618.

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An explicit Lagrangian description is given for the Heisenberg equation on the algebra of operators of a quantum system, and for the Landau–von Neumann equation on the manifold of quantum states which are isospectral with respect to a fixed reference quantum state.
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18

Kurapothula, Pawan K. J., Sam Shepherd, and David M. Wilkins. "Hydrogen-bonding and nuclear quantum effects in clays." Journal of Chemical Physics 156, no. 8 (2022): 084702. http://dx.doi.org/10.1063/5.0083075.

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Hydrogen bonds are of paramount importance in the chemistry of clays, mediating the interaction between the clay surface and water, and for some materials between separate layers. It is well-established that the accuracy of a computational model for clays depends on the level of theory at which the electronic structure is treated. However, for hydrogen-bonded systems, the motion of light H nuclei on the electronic potential energy surface is often affected by quantum delocalization. Using path integral molecular dynamics, we show that nuclear quantum effects lead to a relatively small change in the structure of clays, but one that is comparable to the variation incurred by treating the clay at different levels of electronic structure theory. Accounting for quantum effects weakens the hydrogen bonds in clays, with H-bonds between different layers of the clay affected more than those within the same layer; this is ascribed to the fact that the confinement of an H atom inside a layer is independent of its participation in hydrogen-bonding. More importantly, the weakening of hydrogen bonds by nuclear quantum effects causes changes in the vibrational spectra of these systems, significantly shifting the O–H stretching peaks and meaning that in order to fully understand these spectra by computational modeling, both electronic and nuclear quantum effects must be included. We show that after reparameterization of the popular clay forcefield CLAYFF, the O–H stretching region of their vibrational spectra better matches the experimental one, with no detriment to the model’s agreement with other experimental properties.
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19

Villaseco Arribas, Evaristo, Federica Agostini, and Neepa T. Maitra. "Exact Factorization Adventures: A Promising Approach for Non-Bound States." Molecules 27, no. 13 (2022): 4002. http://dx.doi.org/10.3390/molecules27134002.

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Modeling the dynamics of non-bound states in molecules requires an accurate description of how electronic motion affects nuclear motion and vice-versa. The exact factorization (XF) approach offers a unique perspective, in that it provides potentials that act on the nuclear subsystem or electronic subsystem, which contain the effects of the coupling to the other subsystem in an exact way. We briefly review the various applications of the XF idea in different realms, and how features of these potentials aid in the interpretation of two different laser-driven dissociation mechanisms. We present a detailed study of the different ways the coupling terms in recently-developed XF-based mixed quantum-classical approximations are evaluated, where either truly coupled trajectories, or auxiliary trajectories that mimic the coupling are used, and discuss their effect in both a surface-hopping framework as well as the rigorously-derived coupled-trajectory mixed quantum-classical approach.
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20

Wang, Li Wei. "Atom the Electronic Structure and Atomic Extranuclear Movement State of Research." Advanced Materials Research 554-556 (July 2012): 374–78. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.374.

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Based on the Planck's quantum hypothesis and the Einstein's light quantum hypothesis , the Zhongjizi (a new elementary particles) hypothesis is proposed. It revealed the quantum nature of light. Light quantum (which is photon) was essentially a collection of Zhongjizi, light was constituted of Zhongjizi, the essence of light was the nature of particle, and the quantum nature of light was essentially the Zhongjizi nature of light. The quantum nature of light revealed out: atomic spectra was produced by the light of different frequencies that emitted and absorbed by the extranuclear electrons of different motion states (different rotation frequencies) under certain conditions. The rotation frequency of extranuclear electrons was equal to the frequencies of light that emitted and absorbed by the electrons. By using this law, and according to the atomic spectra, we can know the state of the electron structure of atoms and the movement of electrons ,according to the frequency (the cycle )that rotate round the nuclear of the extranuclear electron in a state of motion , and the relationship of the distance between the electrons and the atomic nucleus .
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21

Richings, Gareth W., and Scott Habershon. "Analyzing Grid-Based Direct Quantum Molecular Dynamics Using Non-Linear Dimensionality Reduction." Molecules 26, no. 24 (2021): 7418. http://dx.doi.org/10.3390/molecules26247418.

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Grid-based schemes for simulating quantum dynamics, such as the multi-configuration time-dependent Hartree (MCTDH) method, provide highly accurate predictions of the coupled nuclear and electronic dynamics in molecular systems. Such approaches provide a multi-dimensional, time-dependent view of the system wavefunction represented on a coordinate grid; in the case of non-adiabatic simulations, additional information about the state populations adds a further layer of complexity. As such, wavepacket motion on potential energy surfaces which couple many nuclear and electronic degrees-of-freedom can be extremely challenging to analyse in order to extract physical insight beyond the usual expectation-value picture. Here, we show that non-linear dimensionality reduction (NLDR) methods, notably diffusion maps, can be adapted to extract information from grid-based wavefunction dynamics simulations, providing insight into key nuclear motions which explain the observed dynamics. This approach is demonstrated for 2-D and 9-D models of proton transfer in salicylaldimine, as well as 8-D and full 12-D simulations of cis-trans isomerization in ethene; these simulations demonstrate how NLDR can provide alternative views of wavefunction dynamics, and also highlight future developments.
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22

CIARAMICOLI, G., I. MARZOLI, and P. TOMBESI. "QUBIT DECOHERENCE IN A NUCLEAR MAGNETIC RESONANCE-LIKE QUANTUM PROCESSOR WITH TRAPPED PARTICLES." International Journal of Modern Physics B 20, no. 11n13 (2006): 1699–710. http://dx.doi.org/10.1142/s0217979206034236.

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We present an in-depth analysis of a potentially significant source of decoherence for a quantum processor, we proposed in our previous paper.1 The processor consists of an array of charged particles confined in planar micro-Penning traps. Qubits are encoded in the particle spins, that are mutually coupled as nuclear spins in a nuclear magnetic resonance-molecule. In this paper, we study in detail the de-phasing effect on the qubit dynamics produced by thermal excitations in the cyclotron motion of the particles.
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23

ALLEN, THEODORE J., and ANDREW J. BORDNER. "CHARGED VORTEX DYNAMICS IN GINZBURG–LANDAU THEORY OF THE FRACTIONAL QUANTUM HALL EFFECT." International Journal of Modern Physics A 10, no. 05 (1995): 645–66. http://dx.doi.org/10.1142/s0217751x95000292.

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We write a Ginzburg–Landau Hamiltonian for a charged order parameter interacting with a background electromagnetic field in 2 + 1 dimensions, which we propose as an effective theory for the fractional quantum Hall effect. We further propose to identify vortex excitations of the theory with Laughlin's fractionally charged quasiparticles. Using the method of Lund we derive a collective coordinate action for vortex defects in the order parameter and demonstrate that the vortices are charged. We examine the classical dynamics of the vortices and then quantize their motion, demonstrating that their peculiar classical motion is a result of the fact that the quantum motion takes place in the lowest Landau level. The classical and quantum motion in two-dimensional regions with boundaries is also investigated. The quantum theory is not invariant under magnetic translations. Magnetic translations add total time derivative terms to the collective action, but no extra constants of the motion result.
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24

HARA, OSAMU. "THE INTERNAL MOTION OF SUPERPARTICLE AND THE EQUATION OF MOTION OF SUPERSYMMETRIC PARTNERS." Modern Physics Letters A 10, no. 24 (1995): 1769–76. http://dx.doi.org/10.1142/s0217732395001897.

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The internal motion of the superparticle and the equation of motion of its supersymmetric partners are discussed based on the conservation laws resulting from the invariances possessed by the Lagrangian of the superparticle, one of which is the Lorentz invariance and the other is to be discussed here. It is shown that this leads to the existence of a new quantum number which is related to the spin but gives information independent of it.
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25

Gomez, Thomas A., Mark C. Zammit, Christopher J. Fontes, and Jackson R. White. "A Quantum-mechanical Treatment of Electron Broadening in Strong Magnetic Fields." Astrophysical Journal 951, no. 2 (2023): 143. http://dx.doi.org/10.3847/1538-4357/acda28.

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Abstract Spectral line-shape fitting is an extremely useful tool in determining the gravity of white dwarf stars. This method is so far limited to nonmagnetic white dwarfs largely because the theory of line broadening in high magnetic fields is not as complete as in the nonmagnetic case. Current Stark+Zeeman models treat plasma particles classically and ignore the motion of the nucleus. We develop the formalism for a quantum-mechanical treatment of the perturbing electrons and include the nuclear motion as part of the broadening and explore their relative importance. The conditions we explore are those found in white dwarf and neutron star atmospheres. We find that, contrary to previous studies, the quantized perturbing electrons create more broadening than perturbers on a straight-path trajectory. Additionally, the quantization of the plasma electrons gives rise to resonances away from the line center. The nuclear motion creates an additional electric field, which also leads to an increase in line broadening; however, this effect in neutron star atmospheres is not as large as previously estimated. This suggests that neutron star spectral lines are sensitive to density and that their mass and radius can be obtained from spectral line fitting, which would help constrain the neutron star equation of state.
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26

Mátyus, Edit, and Stefan Teufel. "Effective non-adiabatic Hamiltonians for the quantum nuclear motion over coupled electronic states." Journal of Chemical Physics 151, no. 1 (2019): 014113. http://dx.doi.org/10.1063/1.5097899.

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27

Ando, Hideo, and Yoshihide Nakao. "Quantum states of the endohedral fullerene Li+@C60 surrounded by anions: energy decomposition analysis of nuclear wave functions." Physical Chemistry Chemical Physics 23, no. 16 (2021): 9785–803. http://dx.doi.org/10.1039/d1cp00056j.

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28

SRISAWAD, PORNRAD, YU-MING ZHENG, YUPENG YAN, CHINORAT KOBDAJ, and YONG-ZHONG XING. "COLLECTIVE FLOW IN HEAVY-ION COLLISIONS FOR Eb=0.25-1.15GeV/NUCLEON." Modern Physics Letters A 24, no. 11n13 (2009): 1063–66. http://dx.doi.org/10.1142/s0217732309000607.

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The study of the various collective flows of nuclear matter is one of the main subjects in heavy ion physics. The interest in collective nuclear motion under extreme conditions, like high density and/or high temperature originates from the equation of state (EOS) of nuclear matter. We investigate the collective transverse flow in heavy ion collisions at incident energies of 0.25 A GeV to 1.15 A GeV for Au + Au system within the quantum molecular dynamical (QMD) model. Some preliminary results are given and discussed.
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29

NAMSRAI, KH, YA HULREE, and N. NJAMTSEREN. "AN OVERVIEW OF THE APPLICATION OF THE LANGEVIN EQUATION TO THE DESCRIPTION OF BROWNIAN AND QUANTUM MOTIONS OF A PARTICLE." International Journal of Modern Physics A 07, no. 12 (1992): 2661–77. http://dx.doi.org/10.1142/s0217751x92001198.

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A simple scheme of unified description of different physical phenomena by using the Langevin type equations is reviewed. Within this approach much attention is being paid to the study of Brownian and quantum motions. Stochastic equations with a white noise term give all characteristics of the Brownian motion. Some generalization of the Langevin type equations allows us to obtain nonlinear equations of particles' motion, which are formally equivalent to the Schrödinger equation. Thus, we establish Nelson's stochastic mechanics on the basis of the Langevin equation.
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30

Vander Griend, Peter. "Bottomonium observables in an open quantum system using the quantum trajectories method." EPJ Web of Conferences 258 (2022): 05005. http://dx.doi.org/10.1051/epjconf/202225805005.

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We solve the Lindblad equation describing the Brownian motion of a Coulombic heavy quark-antiquark pair in a strongly coupled quark gluon plasma using the Monte Carlo wave function method. The Lindblad equation has been derived in the framework of pNRQCD and fully accounts for the quantum and non-Abelian nature of the system. The hydrodynamics of the plasma is realistically implemented through a 3+1D dissipative hydrodynamics code. We compute the bottomonium nuclear modification factor and elliptic flow and compare with the most recent LHC data. The computation does not rely on any free parameter, as it depends on two transport coefficients that have been evaluated independently in lattice QCD. Our final results, which include late-time feed down of excited states, agree well with the available data from LHC 5.02 TeV PbPb collisions.
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31

MEURICE, YANNICK. "THE CLASSICAL HARMONIC OSCILLATOR ON GALOIS AND P-ADIC FIELDS." International Journal of Modern Physics A 04, no. 09 (1989): 2211–33. http://dx.doi.org/10.1142/s0217751x89000881.

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Starting from a difference equation corresponding to the harmonic oscillator, we discuss various properties of the classical motion (cycles, conserved quantity, boundedness, continuum limit) when the dynamical variables take their values on Galois or p-adic fields. We show that these properties can be applied as a technical tool to calculate the motion on the real numbers. On the other hand, we also give an example where the motions over Galois and p-adic fields have a direct physical interpretation. Some perspectives for quantum field theory and strings are briefly discussed.
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32

Pereyaslavets, Leonid, Igor Kurnikov, Ganesh Kamath, et al. "On the importance of accounting for nuclear quantum effects in ab initio calibrated force fields in biological simulations." Proceedings of the National Academy of Sciences 115, no. 36 (2018): 8878–82. http://dx.doi.org/10.1073/pnas.1806064115.

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In many important processes in chemistry, physics, and biology the nuclear degrees of freedom cannot be described using the laws of classical mechanics. At the same time, the vast majority of molecular simulations that employ wide-coverage force fields treat atomic motion classically. In light of the increasing desire for and accelerated development of quantum mechanics (QM)-parameterized interaction models, we reexamine whether the classical treatment is sufficient for a simple but crucial chemical species: alkanes. We show that when using an interaction model or force field in excellent agreement with the “gold standard” QM data, even very basic simulated properties of liquid alkanes, such as densities and heats of vaporization, deviate significantly from experimental values. Inclusion of nuclear quantum effects via techniques that treat nuclear degrees of freedom using the laws of classical mechanics brings the simulated properties much closer to reality.
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33

Lacelle, Serge. "Article." Canadian Journal of Chemistry 77, no. 11 (1999): 1745–51. http://dx.doi.org/10.1139/v99-150.

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The behavior of multiple spin dynamics under time-reversal excitation is investigated in strongly dipolar coupled spin networks. It is demonstrated that the typical physical intuition that NMR spectroscopists have of time-reversal in such systems is erroneous. By studying the equation of motion of the spin system in an infinite one-dimensional quantum spin chain with nearest-neighbor dipolar interactions and evolving under time-reversal excitation, a more appropriate physical picture emerges. Implications of these new findings are briefly discussed in the context of error propagation and teleportation in NMR quantum information processing.Key words: time-reversal, NMR, nuclear spin dynamic, quantum information processing.
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34

ANGLIN, JAMES, and SALMAN HABIB. "CLASSICAL DYNAMICS FOR LINEAR SYSTEMS: THE CASE OF QUANTUM BROWNIAN MOTION." Modern Physics Letters A 11, no. 32n33 (1996): 2655–62. http://dx.doi.org/10.1142/s0217732396002654.

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The dynamics of linear quantum systems is classical in the Wigner representation, yet linear problems are often analyzed using such general techniques as influence functionals and Bogoliubov transformations. In fact, the classical equations of motion provide a simpler and more intuitive formalism for these systems. As an important example, we show that quantum Brownian dynamics in the independent oscillator model is described directly and completely by a c-number Langevin equation. The corresponding Fokker-Planck equation is always local in time, regardless of the environmental spectrum.
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35

GOLUBTSOVA, G. A., and M. B. MENSKY. "QUANTUM NONDEMOLITION MEASUREMENTS FROM PATH INTEGRAL." International Journal of Modern Physics A 04, no. 11 (1989): 2733–50. http://dx.doi.org/10.1142/s0217751x89001059.

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The path integration method is applied to continuous quantum nondemolition (QND) measurements. Direct and indirect QND measurements are considered. It is shown that an observable is QND variable then and only then if the equation of motion for this observable due to a special “effective Hamiltonian” coincides with the classical equation of motion for this observable. The method is developed for finding a class of QND variables in the case of quadratic Hamiltonian.
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36

da Silva, Robson, Diego A. Hoff, and Luis G. C. Rego. "Coupled quantum-classical method for long range charge transfer: relevance of the nuclear motion to the quantum electron dynamics." Journal of Physics: Condensed Matter 27, no. 13 (2015): 134206. http://dx.doi.org/10.1088/0953-8984/27/13/134206.

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37

Choi, Jeong-Ryeol. "Characterizing Quantum Effects in Optically Induced Nanowire Self-Oscillations: Coherent Properties." Photonics 8, no. 7 (2021): 237. http://dx.doi.org/10.3390/photonics8070237.

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Mechanical properties of metallic-nanowire self-oscillations are investigated through a coherent-state analysis. We focus on elucidating the time behavior of quantum energy in such oscillations, in addition to the analysis of fluctuations, evolution of eigenstates, and oscillatory trajectories. The quantum energy varies somewhat randomly at first, but, at a later time, it undergoes a stable periodical oscillation; the mean energy in the stabilized motion is large when the frequency of the driving force is resonated with that of the intrinsic oscillation of the nanowire. We confirmed that when the oscillatory amplitude is sufficiently low, the quantum energy is quite different from the classical one due to zero-point energy, which appears in the quantum regime. Because the power in such an oscillation is typically ultra low, quantum effects in the nanowire oscillations are non-negligible. Detailed analysis for the evolution of the probability densities and their relation with the oscillation trajectories of the nanowire are also carried out. Characterizing quantum effects in the actual oscillatory motions and clarifying their difference from the classical ones are important in understanding nanowire self-oscillations.
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38

Jalalzadeh, Shahram, and A. J. S. Capistrano. "Bohmian mechanics of Klein–Gordon equation via quantum metric and mass." Modern Physics Letters A 34, no. 33 (2019): 1950270. http://dx.doi.org/10.1142/s0217732319502705.

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The causal stochastic interpretation of relativistic quantum mechanics has the problems of superluminal velocities, motion backward in time and the incorrect non-relativistic limit. In this paper, according to the original ideas of de Broglie, Bohm and Takabayasi, we introduce simultaneously a quantum mass and a quantum metric of a curved spacetime to obtain a correct relativistic theory free of mentioned problems.
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39

ISHIHARA, H., S. MORITA, and H. SATO. "QUANTUM BOUNCE OF A UNIFORM DUST STAR IN NEWTON GRAVITY." Modern Physics Letters A 06, no. 10 (1991): 855–59. http://dx.doi.org/10.1142/s0217732391000890.

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We investigate the quantum dynamics of a dust sphere collapsing uniformly in Newtonian gravity, in which the concept of time is obvious. The quantum bounce of the wave packet is observed by a numerical method. Our Newton Lagrangian is different from the Newtonian limit of the Einstein Lagrangian. They give the same classical equation of motion but derive the different quantum systems.
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40

Polley, Kritanjan, and Roger F. Loring. "Two-dimensional vibronic spectroscopy with semiclassical thermofield dynamics." Journal of Chemical Physics 156, no. 12 (2022): 124108. http://dx.doi.org/10.1063/5.0083868.

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Thermofield dynamics is an exactly correct formulation of quantum mechanics at finite temperature in which a wavefunction is governed by an effective temperature-dependent quantum Hamiltonian. The optimized mean trajectory (OMT) approximation allows the calculation of spectroscopic response functions from trajectories produced by the classical limit of a mapping Hamiltonian that includes physical nuclear degrees of freedom and other effective degrees of freedom representing discrete vibronic states. Here, we develop a thermofield OMT (TF-OMT) approach in which the OMT procedure is applied to a temperature-dependent classical Hamiltonian determined from the thermofield-transformed quantum mapping Hamiltonian. Initial conditions for bath nuclear degrees of freedom are sampled from a zero-temperature distribution. Calculations of two-dimensional electronic spectra and two-dimensional vibrational–electronic spectra are performed for models that include excitonically coupled electronic states. The TF-OMT calculations agree very closely with the corresponding OMT results, which, in turn, represent well benchmark calculations with the hierarchical equations of motion method.
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41

Wang, Zisheng, and Hui Pan. "Geometric phase carried by the observables and its application to quantum computation." Quantum Information and Computation 15, no. 11&12 (2015): 951–61. http://dx.doi.org/10.26421/qic15.11-12-5.

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We investigate geometric phases in terms of Heisenberg equation. We find that, equivalently to Schr\"odinger picture with a memory of its motion in terms of the geometric phase factor contained in the wave function, the observales carry with the geometric message under their evolutions in the Heisenberg picture. Such an intrinsic geometric feature may be particularly useful to implement the multi-time correlation geometric quantum gate in terms of the observables, which leads to a possible reduction in experimental errors as well as gate timing. An application is discussed for nuclear-magnetic-resonance system, where the geometric quantum gate is proposed.
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42

SALESI, GIOVANNI. "SPIN AND MADELUNG FLUID." Modern Physics Letters A 11, no. 22 (1996): 1815–23. http://dx.doi.org/10.1142/s0217732396001806.

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Starting from the Pauli current we obtain the decomposition of the nonrelativistic local velocity in two parts: one parallel and the other orthogonal to the impulse. The former is recognized as the “classical” part, that is, the velocity of the center-of-mass, and the latter the “quantum” one, that is, the velocity of the motion in the center-of-mass frame (namely, the internal “spin motion” or zitterbewegung), Inserting the complete expression of the velocity into the kinetic energy term of the classical nonrelativistic (i.e. Newtonian) Lagrangian, we straightforwardly get the appearance of the so-called quantum potential associated, as it is known, to the Madelung fluid. In such a way, the quantum mechanical behavior of particles appears to be strictly correlated to the existence of spin and zitterbewegung.
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43

SAMSONOV, BORIS F. "TIME-DEPENDENT PARASUPERSYMMETRY IN QUANTUM MECHANICS." Modern Physics Letters A 11, no. 26 (1996): 2095–104. http://dx.doi.org/10.1142/s0217732396002083.

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Parasupersymmetry of the one-dimensional time-dependent Schrödinger equation is established. It is intimately connected with a chain of the time-dependent Darboux transformations. As an example a parasupersymmetric model of nonrelativistic free particle with threefold degenerate discrete spectrum of an integral of motion is constructed.
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44

Cheng, Bingqing, Edgar A. Engel, Jörg Behler, Christoph Dellago, and Michele Ceriotti. "Ab initio thermodynamics of liquid and solid water." Proceedings of the National Academy of Sciences 116, no. 4 (2019): 1110–15. http://dx.doi.org/10.1073/pnas.1815117116.

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Thermodynamic properties of liquid water as well as hexagonal (Ih) and cubic (Ic) ice are predicted based on density functional theory at the hybrid-functional level, rigorously taking into account quantum nuclear motion, anharmonic fluctuations, and proton disorder. This is made possible by combining advanced free-energy methods and state-of-the-art machine-learning techniques. The ab initio description leads to structural properties in excellent agreement with experiments and reliable estimates of the melting points of light and heavy water. We observe that nuclear-quantum effects contribute a crucial 0.2 meV/H2O to the stability of ice Ih, making it more stable than ice Ic. Our computational approach is general and transferable, providing a comprehensive framework for quantitative predictions of ab initio thermodynamic properties using machine-learning potentials as an intermediate step.
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45

Prah, Alja, Peter Ogrin, Janez Mavri, and Jernej Stare. "Nuclear quantum effects in enzymatic reactions: simulation of the kinetic isotope effect of phenylethylamine oxidation catalyzed by monoamine oxidase A." Physical Chemistry Chemical Physics 22, no. 13 (2020): 6838–47. http://dx.doi.org/10.1039/d0cp00131g.

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By using computational techniques for quantizing nuclear motion one can accurately reproduce kinetic isotope effect of enzymatic reactions, as demonstrated for phenylethylamine oxidation catalyzed by the monoamine oxidase A enzyme.
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46

JÁUREGUI, R., C. VILLARREAL, and S. HACYAN. "QUANTUM PHENOMENA BETWEEN UNIFORMLY MOVING PLATES." Modern Physics Letters A 10, no. 07 (1995): 619–25. http://dx.doi.org/10.1142/s0217732395000661.

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The quantum theory of fields with moving boundary conditions in four-dimensional space-time is studied. We consider the particular case of a scalar massless field between two infinite parallel plates moving with constant relative velocity. It is shown that this motion produces squeezed states, and creates 'particles' at the expense of the Casimir energy.
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47

CHEMUDUPATI, SRINIVASA K. C., and VLADIMIR I. TSIFRINOVICH. "OSCILLATING CANTILEVER-DRIVEN ADIABATIC REVERSALS IN A PARAMAGNETIC ATOM WITH THE HYPERFINE INTERACTION." International Journal of Quantum Information 10, no. 05 (2012): 1250058. http://dx.doi.org/10.1142/s021974991250058x.

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We have verified theoretically, an opportunity for the measurement of a nuclear spin state in a paramagnetic atom with oscillating cantilever-driven adiabatic reversals (OSCAR) technique in magnetic resonance force microscopy (MRFM), which has been applied for a single electron spin detection. We have developed a semi-classical approach, where the electron–nuclear spin system is treated as a quantum mechanical one while the motion of a ferromagnetic particle on the cantilever tip is considered classically. Our computations support the idea of the measurement of a nuclear spin state by detection of a single electron spin. The effect of magnetic noise is also discussed.
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48

Pervushin, V. N., and V. A. Zinchuk. "Bogolyubov’s integrals of motion in quantum cosmology and gravity." Physics of Atomic Nuclei 70, no. 3 (2007): 593–600. http://dx.doi.org/10.1134/s1063778807030210.

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49

Kadmensky, S. G. "Quantum properties of deformation modes of fissile-nucleus motion." Physics of Atomic Nuclei 71, no. 7 (2008): 1193–99. http://dx.doi.org/10.1134/s1063778808070107.

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50

Nakazawa, Hiroshi. "Quantum brownian motion, irreversibility and non-equilibrium stationary states." Nuclear Physics B - Proceedings Supplements 5, no. 1 (1988): 255–60. http://dx.doi.org/10.1016/0920-5632(88)90051-5.

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