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The Unruh effect--the prediction that an accelerated observer perceives the vacuum as a thermal bath--remains one of the most profound yet experimentally unverified consequences of quantum field theory. This work analyzes a model for the…

General Relativity and Quantum Cosmology · Physics 2025-10-24 Vladimir Toussaint --

We perform a nonperturbative analysis of a charge qubit in a double quantum dot structure coupled to its detector. We show that strong detector-dot interaction tends to slow down and halt coherent oscillations. The transitions to a…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Udo Hartmann , Frank K. Wilhelm

In a flat spacetime with one spatial dimension compactified, inertial reference frames are not all equivalent, but there are the preferred ones. This paper investigates the nonequivalence of inertial frames and also that of uniformly…

General Relativity and Quantum Cosmology · Physics 2018-06-20 Dah-Wei Chiou

Vacuum fluctuations of quantum fields provide an unavoidable environment for any quantum system coupled to it. We study the interplay between boundary conditions and acceleration in determining decoherence of a two-level Unruh-DeWitt…

General Relativity and Quantum Cosmology · Physics 2026-04-06 Harkirat Singh Sahota , Shagun Kaushal , Kinjalk Lochan

We consider a macroscopic quantum system such as a qubit, interacting with a bath of fermions as in the Fr\"ohlich polaron model. The interaction Hamiltonian is thus linear in the macroscopic system variable, and bilinear in the fermions.…

Quantum Physics · Physics 2020-07-16 Erik Aurell , Jan Tuziemski

We analyze a quantum heat engine described by the full Dicke model. The system exhibit quantum phase transitions under certain conditions. We consider the system performing a Stirling thermodynamic cycle. We obtain an enhancement of…

Quantum Physics · Physics 2024-09-18 M. Aparicio Alcalde , E. Arias , N. F. Svaiter

An object moving with the acceleration will change the temperature of environment around it, because of the presence of the Unruh thermal effect. In this work, we investigate the impact of Unruh thermal noise on the quantum-memory-assisted…

General Relativity and Quantum Cosmology · Physics 2024-11-26 Yu-Kun Zhang , Li-Juan Li , Xue-Ke Song , Liu Ye , Dong Wang

The charging of a quantum battery by a four-stroke quantum machine that works either as an engine or a refrigerator is investigated. The presented analysis provides the energetic behavior of the combined system in terms of the heat and…

Quantum Physics · Physics 2022-11-11 Jeongrak Son , Peter Talkner , Juzar Thingna

For finite-time quantum Otto heat engine with working fluid consisting of either a (i) qubit or (ii) a harmonic oscillator, we show that the relative fluctuation of output work is always greater than the corresponding relative fluctuation…

Statistical Mechanics · Physics 2021-06-30 Sushant Saryal , Bijay Kumar Agarwalla

Given a quantum heat engine that operates in a cycle that reaches maximal efficiency for a time-dependent Hamiltonian H(t) of the working substance, with overall controllable driving H(t) = g(t) H, we study the deviation of the efficiency…

For a four-stroke asymmetrically driven quantum Otto engine with working medium modeled by a single qubit, we study the bounds on non-equilibrium fluctuations of work and heat. We find strict relations between the fluctuations of work and…

Statistical Mechanics · Physics 2023-08-02 Sandipan Mohanta , Madhumita Saha , B. Prasanna Venkatesh , Bijay Kumar Agarwalla

A quantum engine with n qubits performing thermodynamic cycles with two thermal reservoirs is presented. While such constructions have been aplenty, here we show the existence of what we term as "limit cycle" at a purely quantum level of…

Quantum Physics · Physics 2024-12-05 Debadrito Roy , Sudhir Ranjan Jain

We study the quantum metrology for a pair of entangled Unruh-Dewitt detectors when one of them is accelerated and coupled to a massless scalar field. Comparing with previous schemes, our model requires only local interaction and avoids the…

Quantum Physics · Physics 2016-06-10 Jieci Wang , Zehua Tian , Jiliang Jing , Heng Fan

We propose a recipe for demonstrating an autonomous quantum heat engine where the working fluid consists of a harmonic oscillator, the frequency of which is tuned by a driving mode. The working fluid is coupled two heat reservoirs each…

Quantum Physics · Physics 2024-04-09 Miika Rasola , Mikko Möttönen

We consider the response of an Unruh detector to scalar fields in an expanding space-time. When combining transition elements of the scalar field Hamiltonian with the interaction operator of detector and field, one finds at second order in…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Bjorn Garbrecht , Tomislav Prokopec

From the thermodynamic equilibrium properties of a two-level system with variable energy-level gap $\Delta$, and a careful distinction between the Gibbs relation $dE = T dS + (E/\Delta) d\Delta$ and the energy balance equation $dE = \delta…

Quantum Physics · Physics 2014-01-22 Gian Paolo Beretta

Quantum thermodynamic relationships in emerging nanodevices are significant but often complex to deal with. The application of machine learning in quantum thermodynamics has provided a new perspective. This study employs reinforcement…

Quantum Physics · Physics 2024-03-06 Gao-xiang Deng , Haoqiang Ai , Bingcheng Wang , Wei Shao , Yu Liu , Zheng Cui

We study the thermodynamic performance of the finite-time non-regenerative Stirling cycle used as a quantum heat engine. We consider specifically the case in which the working substance (WS) is a two-level system. The Stirling cycle is made…

We study the thermalization of smeared particle detectors that couple locally to $any$ operator in a quantum field theory in curved spacetimes. We show that if the field state satisfies the KMS condition with inverse temperature $\beta$…

Quantum Physics · Physics 2021-09-07 T. Rick Perche

A simple but powerful particle detector model consists of a two-level system coupled to a field, where the detected particles are the field excitations. This is known as the Unruh-DeWitt detector. Research using this model has often focused…

Quantum Physics · Physics 2022-07-22 Carolyn E. Wood , Magdalena Zych
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