English
Related papers

Related papers: Reservoir-Free Decoherence in Flying Qubits

200 papers

We present a rigorous analysis of the phenomenon of decoherence for general $N-$level systems coupled to reservoirs. The latter are described by free massless bosonic fields. We apply our general results to the specific cases of the qubit…

Quantum Physics · Physics 2009-11-13 M. Merkli , I. M. Sigal , G. P. Berman

We consider a composite system consisting of coupled particles, and investigate decoherence due to coupling of the center-of-mass degree of freedom with the internal degrees of freedom. For a simple model of two bound particles, we show…

Quantum Physics · Physics 2016-11-30 Todd A. Brun , Leonard Mlodinow

We study the dynamics of a macroscopic superconducting qubit coupled to two independent non-stationary reservoirs by using time-dependent perturbation theory. We show that an equilibrium environment surpasses the coherent evolution of the…

Quantum Physics · Physics 2018-12-13 Nasim Shahmansoori , Farhad Taher Ghahramani , Afshin Shafiee

Without wasting time and effort on philosophical justifications and implications, we write down the conditions for the Hamiltonian of a quantum system for rendering it mathematically equivalent to a deterministic system. These are the…

Quantum Physics · Physics 2020-06-09 Gerard t Hooft

We consider a free quantum particle in one dimension whose mass profile exhibits jump discontinuities. The corresponding Hamiltonian is a self-adjoint realisation of the kinetic-energy operator, with the specific realisation determined by…

Mathematical Physics · Physics 2026-04-27 Fabio Deelan Cunden , Giovanni Gramegna , Marilena Ligabò

We study the interaction of a two-level atom and two fields, one of them classical. We obtain an effective Hamiltonian for this system by using a method recently introduced that produces a small rotation to the Hamiltonian that allows to…

Quantum Physics · Physics 2013-12-04 R. Juárez-Amaro , J. L. Escudero-Jiménez , H. Moya-Cessa

Decoherence may significantly affect the polarization state of optical pulses propagating in dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the pulse. Here we report on the…

We present a rigorous analysis of the phenomenon of decoherence for general N-level systems coupled to reservoirs of free massless bosonic fields. We apply our general results to the specific case of the qubit. Our approach does not involve…

Quantum Physics · Physics 2015-06-26 M. Merkli , I. M. Sigal , G. P. Berman

It has been recently argued that near-integrable nonautonomous one-degree-of-freedom Hamiltonian systems are constrained by KAM theory even when the time-dependent (nonintegrable) part of the Hamiltonian is given in the form of a…

Chaotic Dynamics · Physics 2007-05-23 F. J. Beron-Vera , M. J. Olascoaga , M. G. Brown

A theory recently proposed by the author aims to explain decoherence and the thermodynamical behaviour of closed systems within a conservative, unitary, framework for quantum gravity by assuming that the operators tied to the gravitational…

High Energy Physics - Theory · Physics 2010-04-06 Bernard S. Kay

We revisit the problem of switching off unwanted phase evolution and decoherence in a single two-state quantum system in the light of recent results on random dynamical decoupling methods [L. Viola and E. Knill, Phys. Rev. Lett. {\bf 94},…

Quantum Physics · Physics 2009-11-11 Lea F. Santos , Lorenza Viola

The holographic principle and the thermodynamics of de Sitter space suggest that the total number of fundamental degrees of freedom associated with any finite-volume region of space may be finite. The naive picture of a short distance…

High Energy Physics - Theory · Physics 2009-11-11 Federico Piazza

We present here a set of lecture notes on quantum systems with time-dependent boundaries. In particular, we analyze the dynamics of a non-relativistic particle in a bounded domain of physical space, when the boundaries are moving or…

Mathematical Physics · Physics 2015-05-08 Sara Di Martino , Paolo Facchi

The construction of exactly-solvable models has recently been advanced by considering integrable $T\bar{T}$ deformations and related Hamiltonian deformations in quantum mechanics. We introduce a broader class of non-Hermitian Hamiltonian…

High Energy Physics - Theory · Physics 2023-01-18 Apollonas S. Matsoukas-Roubeas , Federico Roccati , Julien Cornelius , Zhenyu Xu , Aurelia Chenu , Adolfo del Campo

The physics of a quantum system with many degrees of freedom is often approximated by downfolding: most of the degrees of freedom are "folded into" a much smaller number of degrees of freedom, resulting in an effective Hamiltonian that…

Quantum Physics · Physics 2025-06-23 Troy Van Voorhis

We find the conditions for one quantum system to function as a classical controller of another quantum system: the controller must be an open system and rapidly diagonalised in the basis of the controller variable that is coupled to the…

Quantum Physics · Physics 2015-06-03 G J Milburn

We analyze the time evolution of an initial spatial coherence for a two level atom whose internal degrees of freedom interact with a single mode of a cavity field. When the qubit-field subsystem is taken as an environment, the translational…

Quantum Physics · Physics 2009-07-13 A. Vaglica , G. Vetri

We present and experimentally implement a real-time protocol for calibrating the frequency of a resonantly driven qubit, achieving exponential scaling in calibration precision with the number of measurements, up to the limit imposed by…

The simulation of quantum transport in a realistic, many-particle system is a nontrivial problem with no quantitatively satisfactory solution. While real-time propagation has the potential to overcome the shortcomings of conventional…

Mesoscale and Nanoscale Physics · Physics 2015-10-16 Justin E. Elenewski , Yanxiang Zhao , Hanning Chen

We consider the quantum dynamics of a test particle in noncommutative space under the influence of linearized gravitational waves in the long wave-length and low-velocity limit. A prescription for quantizing the classical Hamiltonian for…

High Energy Physics - Theory · Physics 2009-11-18 Anirban Saha , Sunandan Gangopadhyay