English
Related papers

Related papers: An exactly solvable relativistic quantum Otto engi…

200 papers

Unlike classical systems, a measurement performed on a quantum system always alters its state. In this work, the impacts of two diagnostic schemes to determine the performance of quantum Otto heat engines are compared: In one scheme, the…

Quantum Physics · Physics 2021-11-16 Jeongrak Son , Peter Talkner , Juzar Thingna

We apply advanced methods of control theory to open quantum systems and we determine finite-time processes which are optimal with respect to thermodynamic performances. General properties and necessary conditions characterizing optimal…

Quantum Physics · Physics 2018-08-01 Vasco Cavina , Andrea Mari , Alberto Carlini , Vittorio Giovannetti

In this work, we investigate the velocity effects on information degradation due to the Unruh effect in accelerated quantum systems (with finite interaction time). We consider a detector moving along a spatial trajectory within a…

Quantum Physics · Physics 2026-03-19 P. H. M. Barros , Shu-Min Wu , C. A. S. Almeida , H. A. S. Costa

We consider inertial and accelerated Unruh-DeWitt detectors moving in a background thermal bath and calculate their excitation rates. It is shown that for fast moving detectors such a thermal bath does not affect substantially the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Sandro S. Costa , George E. A. Matsas

In finite-time quantum heat engines, some work is consumed to drive a working fluid accompanying coherence, which is called `friction'. To understand the role of friction in quantum thermodynamics, we present a couple of finite-time quantum…

Statistical Mechanics · Physics 2020-02-26 Sangyun Lee , Meesoon Ha , Jong-Min Park , Hawoong Jeong

We consider locally thermal states (for two qubits) with certain amount of quantum entanglement present between them. Unlike previous protocols we show how work can be extracted by performing local unitary operations on this state by…

We consider two-level detectors, coupled to a quantum scalar field, moving inside cavities. We highlight some pathological resonant effects due to abrupt boundaries, and decide to describe the cavity by switching smoothly the interaction by…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Nathaniel Obadia

We study a quantum Otto cycle operating with a time-dependent harmonic oscillator as the working material. We examine the asymmetry present between the two adiabatic processes of the Otto cycle, focusing on cases of sudden expansion and…

Quantum Physics · Physics 2025-03-06 Monika , Shishram Rebari

We derive cooling rate and coefficient of performance as well as their variances for a quantum Otto engine proceeding in finite-time cycle period. This machine consists of two driven strokes, where the system isolated from the heat…

Statistical Mechanics · Physics 2021-08-11 Guangqian Jiao , Shoubao Zhu , Jizhou He , Yongli Ma , Jianhui Wang

We investigate a quantum heat engine with a working substance of two particles, one with a spin $1/2$ and the other with an arbitrary spin (spin $s$), coupled by Heisenberg exchange interaction, and subject to an external magnetic field.…

Quantum Physics · Physics 2016-08-07 Ferdi Altintas , Özgür E. Müstecaplıoğlu

We derive a master equation for the reduced density matrix of a uniformly accelerating quantum detector in arbitrary dimensions, generically coupled to a field initially in its vacuum state, and analyze its late time regime. We find that…

General Relativity and Quantum Cosmology · Physics 2021-09-06 Julio Arrechea , Carlos Barceló , Luis J. Garay , Gerardo García-Moreno

We investigate the thermodynamics of a hybrid quantum device consisting of two qubits collectively interacting with a quantum rotor and coupled dissipatively to two equilibrium reservoirs at different temperatures. By modelling the dynamics…

Quantum Physics · Physics 2024-02-14 Heather Leitch , Kenza Hammam , Gabriele De Chiara

We investigate unitarily inequivalent representations of the algebra of operators in quantum field theory in the cases where there is a Fock representation of the commutation relations. We examine more closely the operational definition of…

High Energy Physics - Theory · Physics 2025-05-15 F. Sobrero , M. S. Soares , T. Guerreiro , N. F. Svaiter

We present a quantum heat engine based on a cavity with two oscillating mirrors that confine a quantum field as the working substance. The engine performs an Otto cycle during which the walls and a field mode interact via a nonlinear…

We study a quantum Otto cycle that uses a 2-qubit working substance whose Hamiltonian does not commute with itself at different times during unitary strokes. We investigate how the cycle responds to the loss of quantum adiabaticity when…

Quantum Physics · Physics 2022-05-03 Cleverson Cherubim , Thiago R. de Oliveira , Daniel Jonathan

Quantum heat machines, encompassing heat engines, refrigerators, heaters, and accelerators, represent the forefront of quantum thermodynamics, offering a novel paradigm for converting heat energy into useful mechanical work. Leveraging…

Quantum Physics · Physics 2024-07-15 He-Guang Xu , Jiasen Jin , Norton G. de Almeida , G. D. de Moraes Neto

In a quantum sense, vacuum is not an empty void but full of virtual particles (fields). It may have long-range properties, be altered, and even undergo phase transitions. It is suggested that long-range properties of a quantum vacuum may be…

High Energy Physics - Theory · Physics 2022-09-28 Shijing Cheng , Wenting Zhou , Hongwei Yu

We consider a finite-time quantum Otto heat engine that consists of two isochoric (thermal-contact) process, where the system is alternatively coupled to a hot squeezed and a cold thermal reservoir, and two unitary driven strokes, where the…

Quantum Physics · Physics 2022-05-27 Yang Xiao , Dehua Liu , Jizhou He , Wu-Ming Liu , Jianhui Wang

In a quantum Stirling heat engine, the heat exchanged with two thermal baths is partly utilized for performing work by redistributing the energy levels of the working substance. We analyze the thermodynamics of a quantum Stirling engine…

Quantum Physics · Physics 2023-08-01 Debmalya Das , George Thomas , Andrew N. Jordan

With the progress of nano-technology, thermodynamics also has to be scaled down, calling for specific protocols to extract and measure work. Usually, such protocols involve the action of an external, classical field (the battery) of…

Quantum Physics · Physics 2016-08-09 Cyril Elouard , Maxime Richard , Alexia Auffèves