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We consider the interaction of a quantum system (spin-1/2) with a macroscopic quantum apparatus (harmonic oscillator) which in turn is coupled to a bath of harmonic oscillators. Exact solutions of the Markovian Master equation show that the…

Quantum Physics · Physics 2009-10-31 Anu Venugopalan

We use molecular dynamics simulations to study the dynamics of an ensemble of interacting self-propelled semi-flexible polymers in contact with a thermal bath. Our intention is to model complex systems of biological interest. We find that…

Soft Condensed Matter · Physics 2011-05-06 Davide Loi , Stefano Mossa , Leticia F. Cugliandolo

We consider a quantum system weakly coupled to a large heat bath of harmonic oscillators. It is well known that such a boson bath initially at thermal equilibrium thermalises the system. We show that assuming a priori an equilibrium state…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. Camalet

We investigate coherent backscattering of light by two harmonically trapped atoms in the light of quantitative quantum duality. Including recoil and Doppler shift close to an optical resonance, we calculate the interference visibility as…

Quantum Physics · Physics 2007-05-23 Christian Wickles , Cord Mueller

Purification is a process in which decoherence is partially reversed by using several input systems which have been subject to the same noise. The purity of the outputs generally increases with the number of input systems, and decreases…

Quantum Physics · Physics 2007-05-23 M. Keyl , R. F. Werner

The quantum dynamics of a two-level system coupled to an Ohmic spin- bath is studied by means of the perturbation approach based on a unitary transformation. A scattering function $\xi_k$ is introduced in the transformation to take into…

Quantum Physics · Physics 2015-05-27 Zhiguo Lü , H. Zheng

We follow the dynamics of an ensemble of interacting self-propelled motorized particles in contact with an equilibrated thermal bath. We find that the fluctuation-dissipation relation allows for the definition of an effective temperature…

Soft Condensed Matter · Physics 2015-05-13 Davide Loi , Stefano Mossa , Leticia F. Cugliandolo

We study a generic open quantum system where the coupling between the system and its environment is of an energy-preserving quantum nondemolition (QND) type. We obtain the general master equation for the evolution of such a system under the…

Quantum Physics · Physics 2007-10-02 Subhashish Banerjee , R. Ghosh

In this work we investigate heat conduction along a ladder-model conformed by two coupled one dimensional lattices with different anharmonicity. We study how the interchain coupling modifies the thermal properties of the isolated systems.…

Statistical Mechanics · Physics 2011-03-18 E. Diaz , R. Gutierrez , G. Cuniberti

We study the quantum dissipative dynamics of a particle coupled linearly to a set of two-level systems (the heat bath) via the master equation method which we extract from the path integral formalism independently from the form of the bath…

Condensed Matter · Physics 2009-10-22 Paulo C. Marques , Antonio H. Castro Neto

We describe quantum behaviors of a simple harmonic oscillator, starting from the classical mechanics. By imposing two conditions on the phase points generated from a symplectic algorithm, we obtain discrete energy levels, satisfying $E_n…

Quantum Physics · Physics 2013-07-02 Sangrak Kim

Linear programming is used as a standard tool for optimising unit commitment or power flows in energy supply systems. For heat supply systems, however, it faces a relevant limitation: For them, energy yield depends on the output…

We consider quenches of a quantum system that is prepared in a canonical equilibrium state of one Hamiltonian and then evolves unitarily in time under a different Hamiltonian. Technically, our main result is a systematic expansion of the…

Statistical Mechanics · Physics 2025-11-14 Lennart Dabelow

In this paper, we examine the thermodynamic behavior of a quantum harmonic oscillator with a position-dependent mass (PDM), where spatial inhomogeneity is modeled through a deformation parameter {\alpha}. Based on the exact energy spectrum,…

Quantum Physics · Physics 2025-05-23 Daniel Sabi Takou , Assimiou Yarou Mora , Gabriel Y. H. Avossevou

We present a systematic study of the purity for Gaussian states of single-mode continuous variable systems. We prove the connection of purity to observable quantities for these states, and show that the joint measurement of two conjugate…

Quantum Physics · Physics 2007-05-23 M. G. A. Paris , F. Illuminati , A. Serafini , S. De Siena

By the topological argument that the identity matrix is surrounded by a set of separable states follows the result that if a system is entangled at thermal equilibrium for some temperature, then it presents a phase transition (PT) where…

Quantum Physics · Physics 2013-08-27 Daniel Cavalcanti , Fernando G. S. L. Brandao , Marcelo O. Terra Cunha

The generation of entanglement between two oscillators that interact via a common reservoir is theoretically studied. The reservoir is modeled by a one-dimensional harmonic crystal initially in thermal equilibrium. Starting from a separable…

Quantum Physics · Physics 2011-09-13 Alexander Wolf , Gabriele De Chiara , Endre Kajari , Eric Lutz , Giovanna Morigi

We consider a particle in the harmonic approximation coupled linearly to an environment. modeled by an infinite set of harmonic oscillators. The system (particle--environment) is considered in a cavity at thermal equilibrium. We employ the…

A classical thermometer typically works by exchanging energy with the system being measured until it comes to equilibrium, at which point the readout is related to the final energy state of the thermometer. A recent paper noted that…

Quantum Physics · Physics 2016-09-07 W. K. Tham , H. Ferretti , A. V. Sadashivan , A. M. Steinberg

We investigate the entanglement properties of thermal states of the harmonic lattice in one, two and three dimensions. We establish the value of the critical temperature for entanglement between neighbouring sites and give physical reasons.…

Quantum Physics · Physics 2009-11-13 Janet Anders