On computing quantum waves exactly from classical action
- URL: http://arxiv.org/abs/2405.06328v7
- Date: Sun, 09 Mar 2025 20:02:06 GMT
- Title: On computing quantum waves exactly from classical action
- Authors: Winfried Lohmiller, Jean-Jacques Slotine,
- Abstract summary: We show that the Schr"odinger equation in quantum mechanics can be solved exactly based on classical least action and classical density.<n>We show that the exact Schr"odinger wave function $Psi$ of the original quantum problem can be constructed by combining this classical multi-valued action $Phi$ with the density $rho$ of the classical position dynamics.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We show that the Schr\"odinger equation in quantum mechanics can be solved exactly based only on classical least action and classical density. Most quantum mechanics problems have classical versions which involve multiple least action solutions. These extremal action paths may stem from spatial inequality constraints (as in the double slit experiment), from singularities in the Hamiltonian (as in a Coulomb potential), or from a closed configuration manifold (as for a spinning particle). We show that the exact Schr\"odinger wave function $\Psi$ of the original quantum problem can be constructed by combining this classical multi-valued action $\Phi$ with the density $\rho$ of the classical position dynamics, which can be computed from $\Phi$ along each extremal action path. This construction is general and does not involve any quasi-classical approximation. Quantum wave collapse corresponds to transitioning between multi-valued action branches at a branch point (position measurement), or to identifying the local branch (momentum measurement). Entanglement corresponds to a sum of individual particle actions mapping to a tensor product of spinors. Examples illustrate how the quantum wave functions for the double-slit experiment, the hydrogen atom, or EPR can be computed exactly from their classical least action counterparts. These coordinate-invariant results provide a simpler computing alternative to Feynman path integrals, as they use only a discrete set of classical paths and avoid zig-zag paths and time-slicing altogether. Since their computation is very different from that of exisiting techniques, they can yield new analytic wave solutions. They extend to the relativistic Klein-Gordon and Dirac equations, and suggest a smooth transition between physics across scales.
Related papers
- Classically estimating observables of noiseless quantum circuits [36.688706661620905]
We present a classical algorithm for estimating expectation values of arbitrary observables on most quantum circuits.
For non-classically-simulable input states or observables, the expectation values can be estimated by augmenting our algorithm with classical shadows of the relevant state or observable.
arXiv Detail & Related papers (2024-09-03T08:44:33Z) - Quantum Hamilton-Jacobi Theory, Spectral Path Integrals and Exact-WKB [0.0]
Hamilton-Jacobi theory is a powerful formalism, but its utility is not explored in quantum theory beyond the correspondence principle.
We propose a new way to perform path integrals in quantum mechanics by using a quantum version of Hamilton-Jacobi theory.
arXiv Detail & Related papers (2024-06-12T02:50:43Z) - Efficient Quantum Simulation Algorithms in the Path Integral Formulation [0.5729426778193399]
We provide two novel quantum algorithms based on Hamiltonian versions of the path integral formulation and another for Lagrangians of the form $fracm2dotx2 - V(x)$.
We show that our Lagrangian simulation algorithm requires a number of queries to an oracle that computes the discrete Lagrangian that scales for a system with $eta$ particles in $D+1$ dimensions, in the continuum limit, as $widetildeO(eta D t2/epsilon)$ if $V(x)$ is bounded
arXiv Detail & Related papers (2024-05-11T15:48:04Z) - Variational-quantum-eigensolver-inspired optimization for spin-chain work extraction [39.58317527488534]
Energy extraction from quantum sources is a key task to develop new quantum devices such as quantum batteries.
One of the main issues to fully extract energy from the quantum source is the assumption that any unitary operation can be done on the system.
We propose an approach to optimize the extractable energy inspired by the variational quantum eigensolver (VQE) algorithm.
arXiv Detail & Related papers (2023-10-11T15:59:54Z) - Classical and semi-classical limits in phase space [0.0]
A semimagnitude approximation is derived by using a family of wavepackets to map arbitrary wavefunctions into phase space.
The resulting approximation is a linear first-order partial differential equation on phase space.
This is a derivation of the Koopman-vonclassicalmann (KvN) formulation of classical mechanics.
arXiv Detail & Related papers (2023-05-29T22:48:45Z) - Revealing quantum effects in bosonic Josephson junctions: a
multi-configuration atomic coherent states approach [1.450405446885067]
We show that quantum effects beyond the mean-field approximation are easily uncovered.
The number of variational trajectories needed for good agreement with full quantum results is orders of magnitude smaller than in the semiclassical case.
arXiv Detail & Related papers (2023-02-10T16:10:20Z) - Correspondence between open bosonic systems and stochastic differential
equations [77.34726150561087]
We show that there can also be an exact correspondence at finite $n$ when the bosonic system is generalized to include interactions with the environment.
A particular system with the form of a discrete nonlinear Schr"odinger equation is analyzed in more detail.
arXiv Detail & Related papers (2023-02-03T19:17:37Z) - Quantum simulation of partial differential equations via
Schrodingerisation [31.986350313948435]
We present a simple new way to simulate general linear partial differential equations via quantum simulation.
Using a simple new transform, referred to as the warped phase transformation, any linear partial differential equation can be recast into a system of Schrodinger's equations.
This can be seen directly on the level of the dynamical equations without more sophisticated methods.
arXiv Detail & Related papers (2022-12-28T17:32:38Z) - Path integral in position-deformed Heisenberg algebra with strong
quantum gravitational measurement [0.0]
We show that quantum gravity bends the paths of particles, allowing them to travel quickly from one point to another.
It is numerically observed by the decrease in values of classical actions as one increases the quantum gravitational effects.
arXiv Detail & Related papers (2022-04-29T14:21:30Z) - Quantum dynamics corresponding to chaotic BKL scenario [62.997667081978825]
Quantization smears the gravitational singularity avoiding its localization in the configuration space.
Results suggest that the generic singularity of general relativity can be avoided at quantum level.
arXiv Detail & Related papers (2022-04-24T13:32:45Z) - Fall of a Particle to the Center of a Singular Potential: Classical vs.
Quantum Exact Solutions [0.0]
We inspect the quantum problem with the help of the conventional Schr"odinger's equation.
Surprisingly, the quantum and classical solutions exhibit striking similarities.
arXiv Detail & Related papers (2022-02-25T11:04:39Z) - A shortcut to adiabaticity in a cavity with a moving mirror [58.720142291102135]
We describe for the first time how to implement shortcuts to adiabaticity in quantum field theory.
The shortcuts take place whenever there is no dynamical Casimir effect.
We obtain a fundamental limit for the efficiency of an Otto cycle with the quantum field as a working system.
arXiv Detail & Related papers (2022-02-01T20:40:57Z) - Path-Integral Treatment of Quantum Bouncers [0.0]
We derive mappings between the one-sided bouncer and symmetric bouncer, which explains why each bounce of the one-sided bouncer increases the Morse index by 2.
We interpret the semiclassical Feynman path integral to obtain visualizations of matter wave propagation based on interference between classical paths.
arXiv Detail & Related papers (2021-09-28T13:24:29Z) - Bernstein-Greene-Kruskal approach for the quantum Vlasov equation [91.3755431537592]
The one-dimensional stationary quantum Vlasov equation is analyzed using the energy as one of the dynamical variables.
In the semiclassical case where quantum tunneling effects are small, an infinite series solution is developed.
arXiv Detail & Related papers (2021-02-18T20:55:04Z) - Probing quantum effects with classical stochastic analogs [0.0]
We propose a method to construct a classical analog of an open quantum system.
The classical analog is made out of a collection of identical wells where classical particles of mass $m$ are trapped.
arXiv Detail & Related papers (2020-12-13T18:02:27Z) - Objective trajectories in hybrid classical-quantum dynamics [0.0]
We introduce several toy models in which to study hybrid classical-quantum evolution.
We present an unravelling approach to calculate the dynamics, and provide code to numerically simulate it.
arXiv Detail & Related papers (2020-11-11T19:00:34Z) - Quantum dynamics and relaxation in comb turbulent diffusion [91.3755431537592]
Continuous time quantum walks in the form of quantum counterparts of turbulent diffusion in comb geometry are considered.
Operators of the form $hatcal H=hatA+ihatB$ are described.
Rigorous analytical analysis is performed for both wave and Green's functions.
arXiv Detail & Related papers (2020-10-13T15:50:49Z) - Probing the Universality of Topological Defect Formation in a Quantum
Annealer: Kibble-Zurek Mechanism and Beyond [46.39654665163597]
We report on experimental tests of topological defect formation via the one-dimensional transverse-field Ising model.
We find that the quantum simulator results can indeed be explained by the KZM for open-system quantum dynamics with phase-flip errors.
This implies that the theoretical predictions of the generalized KZM theory, which assumes isolation from the environment, applies beyond its original scope to an open system.
arXiv Detail & Related papers (2020-01-31T02:55:35Z) - External and internal wave functions: de Broglie's double-solution
theory? [77.34726150561087]
We propose an interpretative framework for quantum mechanics corresponding to the specifications of Louis de Broglie's double-solution theory.
The principle is to decompose the evolution of a quantum system into two wave functions.
For Schr"odinger, the particles are extended and the square of the module of the (internal) wave function of an electron corresponds to the density of its charge in space.
arXiv Detail & Related papers (2020-01-13T13:41:24Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.