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How quantum coherence influences thermodynamic behavior remains an open question in quantum thermodynamics. Here we investigate this relation within the pure dephasing framework, where a central qubit interacts with a finite Ising-like spin…

Quantum Physics · Physics 2026-03-31 Marino P. Lenzarini , Diogo O. Soares-Pinto

The temperature of an oscillator coupled to the vacuum state of a heat bath via ohmic coupling is non-zero, as measured by the reduced density matrix of the oscillator. This paper shows that the actual temperature, as measured by a…

Quantum Physics · Physics 2015-05-30 William G. Unruh

The entanglement between a Pauli-like two-level system and a quantum harmonic oscillator enhanced by an interaction between them and a $\delta$-pulse sequence is studied, with the decoherence due to their coupling with a Markovian bath.…

Quantum Physics · Physics 2008-04-16 Kwan-yuet Ho

The interaction of a quantum system with the environment leads to the so-called quantum decoherence. Beyond its fundamental significance, the understanding and the possible control of this dynamics in various scenarios is a key element for…

Quantum Physics · Physics 2011-09-05 Virginia D'Auria , Noriyuki Lee , Taoufik Amri , Claude Fabre , Julien Laurat

A master equation for the deformed quantum harmonic oscillator interacting with a dissipative environment, in particular with a thermal bath, is derived in the microscopic model by using perturbation theory, for the case when the…

Quantum Physics · Physics 2009-11-13 A. Isar , W. Scheid

We study properties of steady states (states with time-independent density operators) of systems of coupled harmonic oscillators. Formulas are derived showing how adiabatic change of the Hamiltonian transforms one steady state into another.…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Max Tegmark , Leehwa Yeh

A quantum system with discrete and continuos evolution spectrum is studied. A final pointer basis is found, that can be defined in a presised mathematical way. This result is use to explain the quantum measurement in the system.

Quantum Physics · Physics 2007-05-23 M. Castagnino , R. Laura , R. Id Betan

It is discussed the decoherence problems in ensemble large-scale solid state NMR quantum computer based on the array of P donor atoms having nuclear spin I = 1/2. It is considered here, as main mechanisms of decoherence for low temperature…

Quantum Physics · Physics 2009-11-07 A. A. Kokin

Investigations of quantum and mesoscopic thermodynamics force one to answer two fundamental questions associated with the foundations of statistical mechanics: (i) how does macroscopic irreversibility emerge from microscopic reversibility?…

Quantum Physics · Physics 2019-02-20 Wei-Min Zhang

Quantum correlations and coherence generated between two free spinless particles in the lattice, interacting with a common quantum phonon bath, are studied. The reduced density matrix is solved using the Markov approach. We show that the…

Quantum Physics · Physics 2017-05-11 Marco Nizama , Manuel O. Cáceres

In real-time quantum feedback protocols, the record of a continuous measurement is used to stabilize a desired quantum state. Recent years have seen highly successful applications in a variety of well-isolated micro-systems, including…

Quantum Physics · Physics 2018-06-22 D. J. Wilson , V. Sudhir , N. Piro , R. Schilling , A. Ghadimi , T. J. Kippenberg

We identify sufficient conditions on the structure of the interaction Hamiltonian between a two-level quantum system and a thermal bath which, without any external drive or coherent measurement, guarantee the generation of steady-state…

Quantum Physics · Physics 2018-08-22 Giacomo Guarnieri , Michal Kolar , Radim Filip

We study the decoherence of a system of $N$ non-interacting heavy particles (atoms) due to coherent scattering with a background gas. We introduce a framework for computing the induced phase shift and loss of contrast for arbitrary…

Quantum Physics · Physics 2024-09-11 Leonardo Badurina , Clara Murgui , Ryan Plestid

We consider a quantum harmonic oscillator coupled with a graviton bath and discuss the loss of coherence in the matter sector due to the matter-graviton vertex interaction. Working in the quantum-field-theory framework, we obtain a master…

General Relativity and Quantum Cosmology · Physics 2024-04-24 Marko Toroš , Anupam Mazumdar , Sougato Bose

We combine traditional pointer-based simultaneous measurements of conjugate observables with the concept of quantum Brownian motion of multipartite systems to phenomenologically model simultaneous measurements of conjugate observables in a…

Quantum Physics · Physics 2014-05-14 Raoul Heese , Matthias Freyberger

We consider the evolution of a two-state quantum system (a spin 1/2 particle) in both the framework of standard quantum mechanics and under the decoherence regime. The former approach on this issue is the well-known quantum flipping process…

Quantum Physics · Physics 2011-07-21 Afshin Shafiee , Arash Tirandaz

We study the problem of driving an unknown initial mixed quantum state onto a known pure state without using unitary transformations. This can be achieved, in an efficient manner, with the help of sequential measurements on at least two…

Quantum Physics · Physics 2009-11-11 L. Roa , G. Olivares

We study the non-equilibrium dynamics of two coupled mechanical oscillators with general linear couplings to two uncorrelated thermal baths at temperatures $T_1$ and $T_2$, respectively. We obtain the complete solution of the…

Quantum Physics · Physics 2017-07-07 Daniel Boyanovsky , David Jasnow

We demonstrate that the Chebyshev expansion method is a very efficient numerical tool for studying spin-bath decoherence of quantum systems. We consider two typical problems arising in studying decoherence of quantum systems consisting of…

Quantum Physics · Physics 2009-11-10 V. V. Dobrovitski , H. A. De Raedt

A model for a quantum register $\cal R$ made of $N$ replicas of a $d$-dimensional quantum system (cell) coupled with the environment, is studied by means of a Born-Markov Master Equation (ME). Dissipation and decoherence are discussed in…

Quantum Physics · Physics 2011-07-19 Paolo Zanardi