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Related papers: Coherence and squeezing along quantum trajectories

200 papers

One-dimensional discrete-time quantum walk has played an important role in development of quantum algorithms and protocols for different quantum simulations. The speedup observed in quantum walk algorithms is attributed to quantum…

Quantum Physics · Physics 2020-08-14 Shivani Singh , C. M. Chandrashekar

Consider a discrete-time quantum walk on the $N$-cycle subject to decoherence both on the coin and the position degrees of freedom. By examining the evolution of the density matrix of the system, we derive some new conclusions about the…

Quantum Physics · Physics 2011-07-20 Chaobin Liu , Nelson Petulante

Gravitational well is a widely used system for the verification of the quantum weak equivalence principle (WEP). We have studied the quantum gravitational well (GW) under the shed of noncommutative (NC) space so that the results can be…

Quantum Physics · Physics 2022-08-01 Kalpana Biswas , Jyoti Prasad Saha , Pinaki Patra

Quantum coherence in curved spacetime offers a fresh window into the interplay between gravity, thermality, and quantum resources. While previous work has shown that Markovian evolution can generate entanglement and other nonclassical…

General Relativity and Quantum Cosmology · Physics 2025-10-06 Samira Elghaayda , Atta ur Rahman , Mostafa Mansour

Evolution of coherent states is considered for a particle confined to a cylinder moving in a harmonic oscillator potential. Because of the discontinuous changes as time goes by of the phase representing the position of a particle on a…

Quantum Physics · Physics 2013-08-14 K. Kowalski , J. Rembieliński

The sensitivity of the evolution of quantum uncertainties to the choice of the initial conditions is shown via a complex nonlinear Riccati equation leading to a reformulation of quantum dynamics. This sensitivity is demonstrated for systems…

Quantum Physics · Physics 2015-05-27 Hans Cruz , Dieter Schuch , Octavio Castaños , Oscar Rosas-Ortiz

In this paper, we study the role of coherent states in the realm of quantum cosmology, both in a second-quantized single universe and in a third-quantized quantum multiverse. In particular, most emphasis will be paid to the quantum…

General Relativity and Quantum Cosmology · Physics 2010-04-30 S. Robles-Perez , Y. Hassouni , P. F. Gonzalez-Diaz

We analyze in detail the discrete--time quantum walk on the line by separating the quantum evolution equation into Markovian and interference terms. As a result of this separation, it is possible to show analytically that the quadratic…

Quantum Physics · Physics 2009-11-10 A. Romanelli , A. C. Sicardi-Schifino , R. Siri , G. Abal , A. Auyuanet , R. Donangelo

Mapping the system evolution of a two-state system allows the determination of the effective system Hamiltonian directly. We show how this can be achieved even if the system is decohering appreciably over the observation time. A method to…

The stability of quantum systems to perturbations of the Hamiltonian is studied. This stability is quantified by the fidelity. Dependence of fidelity on the initial state as well as on the dynamical properties of the system is considered.…

Quantum Physics · Physics 2007-05-23 Marko Znidaric

A bipartite system whose subsystems are fully quantum chaotic and coupled by a perturbative interaction with a tunable strength is a paradigmatic model for investigating how isolated quantum systems relax towards an equilibrium. It is found…

We use a single squeezed state to represent a qubit, which can be coherently processed in a deconvolution picture (DP) in the presence of noise. We avail ourselves of the fact that when evolution is governed by a quadratic dissipative…

Quantum Physics · Physics 2017-12-01 Allan Tameshtit

We discuss quantum evolution of a decaying state in relation to a recent experiment of Katz et al. Based on exact analytical and numerical solutions of a simple model, we identify a regime where qubit retains coherence over a finite time…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Leonid P. Pryadko , Alexander N. Korotkov

We present an exact analytic study of unitary coherence dynamics in a minimal two qubit superconducting system. By deriving the full time evolution operator and propagating Bell state initial conditions, we obtain closed form time dependent…

Quantum Physics · Physics 2026-05-11 Seyed Mohsen Moosavi Khansari

We study the decoherence process for an open quantum system which is classically chaotic (a quartic double well with harmonic driving coupled to a sea of harmonic oscillators). We analyze the time dependence of the rate of entropy…

Quantum Physics · Physics 2009-11-07 Diana Monteoliva , Juan Pablo Paz

Conventional approaches for controlling open quantum systems use coherent control which affects the system's evolution through the Hamiltonian part of the dynamics. Such control, although being extremely efficient for a large variety of…

Quantum Physics · Physics 2009-05-04 Alexander Pechen , Herschel Rabitz

In this article, we formulate the study of the unitary time evolution of systems consisting of an infinite number of uncoupled time-dependent harmonic oscillators in mathematically rigorous terms. We base this analysis on the theory of a…

Mathematical Physics · Physics 2009-10-06 Daniel Gómez Vergel , Eduardo J. S. Villaseñor

We introduce a new class of quantum models with time-dependent Hamiltonians of a special scaling form. By using a couple of time-dependent unitary transformations, the time evolution of these models is expressed in terms of related systems…

Quantum Physics · Physics 2009-11-07 L. Samaj

Squeezed states of the harmonic oscillator are a common resource in applications of quantum technology. If the noise is suppressed in a nonlinear combination of quadrature operators below threshold for all possible up-to-quadratic…

Quantum Physics · Physics 2023-06-13 Vojtěch Kala , Petr Marek , Radim Filip

We study the full time evolution of one- and two-mode bosonic quantum systems that interact through single- and two-mode squeezing Hamiltonians. We establish that the single- and two-mode cases are formally equivalent, leading to the same…

Quantum Physics · Physics 2018-05-21 Chester Moore , David Edward Bruschi