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Related papers: An Introduction to the Quantum Backflow Effect

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We establish the general framework of quantum fluctuation theorems by finding the symmetry between the forward and backward transitions of any given quantum channel. The Petz recovery map is adopted as the reverse quantum channel, and the…

Quantum Physics · Physics 2019-08-23 Hyukjoon Kwon , M. S. Kim

We study the quantum backflow problem of a relativistic charged Dirac fermion constrained to move on a ring of radius $R$. Using the relativistic current operator we compute the probability flux through a generic time interval to show…

Quantum Physics · Physics 2023-08-14 Valentin Daniel Paccoia , Orlando Panella , Pinaki Roy

Tunneling, though a physical reality, is shrouded in mystery. Wave packets cannot be constructed under the barrier and group velocity cannot be defined. The tunneling particle can be observed on either sides of the barrier but its…

Mesoscale and Nanoscale Physics · Physics 2023-03-01 Kanchan Meena , P. Singha Deo

Quantum retrodiction involves finding the probabilities for various preparation events given a measurement event. This theory has been studied for some time but mainly as an interesting concept associated with time asymmetry in quantum…

Quantum Physics · Physics 2009-11-07 David T. Pegg , Stephen M. Barnett , John Jeffers

Projective measurement is a commonly used assumption in quantum mechanics. However, advances in quantum measurement techniques allow for partial measurements, which accurately estimate state information while keeping the wavefunction…

Quantum Physics · Physics 2021-08-24 Jonathan Monroe

Why do quantum evolutions occur and why do they stop at certain points? In classical thermodynamics affinity was introduced to predict in which direction an irreversible process proceeds. In this paper the quantum mechanical counterpart of…

Quantum Physics · Physics 2018-12-11 B. Ahmadi , S. Salimi , F. Kheirandish , A. S. Khorashad

Students in quantum mechanics class are taught that the wave function contains all knowable information about an isolated system. Later in the course, this view seems to be contradicted by the mysterious density matrix, which introduces a…

General Physics · Physics 2021-04-16 Mark G. Kuzyk

It is shown that the magnetic energy of a quantum current, contrary to the classical case, is essentially negative. Since this result allows to escape a famous theorem by Bloch, it can be expected that, under appropriate conditions, the…

Superconductivity · Physics 2007-05-23 F. Miglietta

We analyze quantum effects occurring in optomechanical systems where the coupling between an optical mode and a mechanical mode is quadratic in displacement (membrane-in-the-middle geometry). We show that it is possible to observe quantum…

Quantum Physics · Physics 2019-05-08 J. D. P. Machado , R. J. Slooter , Ya. M. Blanter

The probability distribution of a time measurement $T_x$ at position $x$ can be inferred from the probability distribution of a position measurement $X_t$ at time $t$ as given by the Born rule [Time-of-arrival distributions for continuous…

Quantum Physics · Physics 2025-07-30 Mathieu Beau , Timothey Szczepanski , Rafael Martellini , Lionel Martellini

We analyze recent approaches to quantum Markovianity and how they relate to the proper definition of quantum memory. We point out that the well-known criterion of information backflow may not correctly report character of the memory falsely…

Quantum Physics · Physics 2020-08-31 Michal Banacki , Marcin Marciniak , Karol Horodecki , Pawel Horodecki

The concept of wavefunction reduction should be introduced to standard quantum mechanics in any physical processes where effective reduction of wavefunction occurs, as well as in the measurement processes. When the overlap is negligible,…

Quantum Physics · Physics 2007-05-23 WonYoung Hwang , Jeong-Young Ji , Jongbae Hong

In classical physics, probabilistic or statistical knowledge has been always related to ignorance or inaccurate subjective knowledge about an actual state of affairs. This idea has been extended to quantum mechanics through a completely…

Quantum Physics · Physics 2016-03-29 Christian de Ronde

Investigation into the applicability of the equivalence principle in quantum mechanics has taken many forms, with varying conclusions. Here, a dynamical semi-classical description of a wave packet in terms of its center of mass and higher…

Quantum Physics · Physics 2023-10-16 Joseph Balsells , Martin Bojowald

The description of a measuring process, such as that which occurs when a quantum point contact (QPC) detector is influenced by a nearby external electron which can take up two possible positions, provides a interesting application of the…

Quantum Physics · Physics 2008-11-26 L. Stodolsky

The quantum mechanics is considered to be a partial case of the stochastic system dynamics. It is shown that the wave function describes the state of statistically averaged system $<\mathcal{S}_{st}>$, but not that of the individual…

General Physics · Physics 2007-05-23 Yuri A. Rylov

Non-Markovian effects in open quantum system dynamics usually manifest backflow of information from the environment to the system, indicating complete-positive divisibility breaking of the dynamics. We provide a criterion for witnessing…

Quantum Physics · Physics 2024-03-04 Bivas Mallick , Saheli Mukherjee , Ananda G. Maity , A. S. Majumdar

We discuss the quantum mechanical description of a gravitational wave interacting with a cavity electromagnetic field. Quantum fluctuations of the gravitational vacuum induce squeezing in the optical field. Moreover, this squeezing…

Quantum Physics · Physics 2020-06-19 Thiago Guerreiro

We show that the phenomenon of anomalous weak values is not limited to quantum theory. In particular, we show that the same features occur in a simple model of a coin subject to a form of classical backaction with pre- and post-selection.…

Quantum Physics · Physics 2014-09-19 Christopher Ferrie , Joshua Combes

An inhomogeneous backflow transformation for many-particle wave functions is presented and applied to electrons in atoms, molecules, and solids. We report variational and diffusion quantum Monte Carlo VMC and DMC energies for various…

Computational Physics · Physics 2008-01-04 P. Lopez-Rios , A. Ma , N. D. Drummond , M. D. Towler , R. J. Needs