Optimization of conveyance of quantum particles by moving potential-well

• URL: http://arxiv.org/abs/2408.04480v1
• Date: Thu, 8 Aug 2024 14:14:48 GMT
• Title: Optimization of conveyance of quantum particles by moving potential-well
• Authors: Satoshi Morita, Yoshiaki Teranishi, Seiji Miyashita,
• Abstract summary: We study the probability of successful conveyance of a particle trapping in a potential-well. For the actual motion of conveyance, we need to accelerate the particle to move and then decelerate it to stop at the destination.
• Score: 0.36868085124383626
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Quantum mechanical control of the position of a particle by using a trapping potential-well is an important problem for the manipulation of a quantum particle. We study the probability of successful conveyance of a particle trapping in a potential-well, i.e., survival probability in the process carrying of the particle for a given length within a given fixed time. For the actual motion of conveyance, we need to accelerate the particle to move and then decelerate it to stop at the destination. First, the relaxation of the survival probability in a constant acceleration rate is studied in detail by direct numerical calculation, the Wentzel-Kramers-Brillouin method, and a method of the resonance states. The survival probability was found to show an exponential decay in a long time, which is analyzed from a viewpoint of eigenvalue problem. An important source of drop-off comes from a non-analytic change of velocity at the starting point. When the rested particle begins to move, the ground state of the rest frame is redistributed to eigenstates of the moving frame, and then, each eigenstate of the moving frame evolves in time. The dephasing of wavefunctions of the distributed populations reduces the probability of successful conveyance. In general, a smooth start gives a small initial disturbance but requires a large acceleration during the process to reach the destination in the fixed time which causes a larger drop-off in the process. Considering these conflicting facts, we study the survival probability in concrete conveyance schemes. We observe the time evolution of the trapped probability and the population distribution during the conveyance process. In cases that the potential-well has several bound states, we propose a method to select the particle trapped at the ground state by making use of the difference of survival probabilities of bound states.

Related papers

• A non-hermitean momentum operator for the particle in a box [49.1574468325115]
  We show how to construct the corresponding hermitean Hamiltonian for the infinite as well as concrete example. The resulting Hilbert space can be decomposed into a physical and unphysical subspace.
  arXiv  Detail & Related papers  (2024-03-20T12:51:58Z)
• Real-time dynamics of false vacuum decay [49.1574468325115]
  We investigate false vacuum decay of a relativistic scalar field in the metastable minimum of an asymmetric double-well potential. We employ the non-perturbative framework of the two-particle irreducible (2PI) quantum effective action at next-to-leading order in a large-N expansion.
  arXiv  Detail & Related papers  (2023-10-06T12:44:48Z)
• Relativistic time-of-arrival measurements: predictions, post-selection and causality problem [0.0]
  We analyze time-of-arrival probability distributions for relativistic particles in the context of quantum field theory (QFT) We show that QFT leads to a unique prediction, modulo post-selection, that incorporates properties of the apparatus into the initial state. We discuss possible ways to restore causality, and we argue that this may not be possible in measurement models that involve switching the field-apparatus coupling on and off.
  arXiv  Detail & Related papers  (2022-10-11T16:24:39Z)
• Stochastic resets in the context of a tight-binding chain driven by an oscillating field [0.0]
  We study in the framework of the driven tight-binding chain (TBC) the issue of quantum unitary dynamics interspersed at random times with resets. We establish the remarkable effect of localization of the TBC particle on the sites of the underlying lattice at long times.
  arXiv  Detail & Related papers  (2022-09-28T14:08:50Z)
• Equilibration and locality [0.0]
  We introduce a Markov-chain based framework over a finite set of microstates. We show that it is possible to construct models obeying and violating strong-locality both for indistinguishable particles and for distinguishable ones.
  arXiv  Detail & Related papers  (2022-06-02T17:09:41Z)
• The influence of the symmetry of identical particles on flight times [0.0]
  symmetry of identical particles can influence the time evolution of free particles in the nonrelativistic and relativistic domains. Fermions arrive earlier than bosons when they are scattered by a delta barrier. Fermions also arrive earlier than bosons when they are scattered by a delta barrier.
  arXiv  Detail & Related papers  (2021-05-31T13:56:40Z)
• Interplay between transport and quantum coherences in free fermionic systems [58.720142291102135]
  We study the quench dynamics in free fermionic systems. In particular, we identify a function, that we dub emphtransition map, which takes the value of the stationary current as input and gives the value of correlation as output.
  arXiv  Detail & Related papers  (2021-03-24T17:47:53Z)
• Variational Transport: A Convergent Particle-BasedAlgorithm for Distributional Optimization [106.70006655990176]
  A distributional optimization problem arises widely in machine learning and statistics. We propose a novel particle-based algorithm, dubbed as variational transport, which approximately performs Wasserstein gradient descent. We prove that when the objective function satisfies a functional version of the Polyak-Lojasiewicz (PL) (Polyak, 1963) and smoothness conditions, variational transport converges linearly.
  arXiv  Detail & Related papers  (2020-12-21T18:33:13Z)
• Unbalanced Sobolev Descent [31.777218621726284]
  We introduce Unbalanced Sobolev Descent (USD), a particle descent algorithm for transporting a high dimensional source distribution to a target distribution that does not necessarily have the same mass. USD transports particles along flows of the witness function of the Sobolev-Fisher discrepancy (advection step) and reweighs the mass of particles with respect to this witness function (reaction step) We show on synthetic examples that USD transports distributions with or without conservation of mass faster than previous particle descent algorithms.
  arXiv  Detail & Related papers  (2020-09-29T16:43:38Z)
• Vacuum Decay Induced by Quantum Fluctuations [0.0]
  We consider two varieties of field fluctuations and their potential effects in a semiclassical description. We find a contribution to the decay rate which is comparable to the decay rate by quantum tunneling. We find a contribution to the decay rate which is much larger than those coming from either quantum tunneling or linear field fluctuations.
  arXiv  Detail & Related papers  (2020-05-17T19:49:03Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)

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.