scholarly journals Stochastic thermodynamics of a finite quantum system coupled to a heat bath

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Heinz-Jürgen Schmidt ◽  
Jürgen Schnack ◽  
Jochen Gemmer
Keyword(s):  
Quantum System ◽  
Heat Bath ◽  
Level System ◽  
Stochastic Thermodynamics ◽  
Cold Bath ◽  
Suitable Temperature ◽  
Hot Bath ◽  
Clausius Relation

Abstract We consider a situation where an N-level system (NLS) is coupled to a heat bath without being necessarily thermalized. For this situation, we derive general Jarzynski-type equations and conclude that heat and entropy is flowing from the hot bath to the cold NLS and, vice versa, from the hot NLS to the cold bath. The Clausius relation between increase of entropy and transfer of heat divided by a suitable temperature assumes the form of two inequalities which have already been considered in the literature. Our approach is illustrated by an analytical example.

Transport coefficients of a quantum system interacting with a squeezed heat bath

2006 ◽  
Vol 74 (1) ◽  
Author(s):  
Sh. A. Kalandarov ◽  
Z. Kanokov ◽  
G. G. Adamian ◽  
N. V. Antonenko
Keyword(s):  
Quantum System ◽  
Transport Coefficients ◽  
Heat Bath

Broadband EM radiation amplification by means of a monochromatically driven two-level system

2017 ◽  
Vol 31 (04) ◽  
pp. 1750027 ◽  
Author(s):  
Andrey V. Soldatov
Keyword(s):  
Dipole Moment ◽  
Quantum System ◽  
High Frequency ◽  
Laser Field ◽  
Diagonal Matrix ◽  
Matrix Elements ◽  
Level System ◽  
Dipole Moment Operator ◽  
Moment Operator ◽  
Radiation Amplification

It is shown that a two-level quantum system possessing dipole moment operator with permanent non-equal diagonal matrix elements and driven by external semiclassical monochromatic high-frequency electromagnetic (EM) (laser) field can amplify EM radiation waves of much lower frequency.

scholarly journals Leggett-Garg Inequalities for Quantum Fluctuating Work

Entropy ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 200 ◽  
Author(s):  
◽  
Keyword(s):  
Quantum System ◽  
Quantum Correlations ◽  
Weak Measurement ◽  
Projective Measurement ◽  
Level System ◽  
Quantum Regime ◽  
Measurement Scheme ◽  
Temporal Correlations ◽  
Classical Thermodynamics ◽  
Work Done

The Leggett-Garg inequalities serve to test whether or not quantum correlations in time can be explained within a classical macrorealistic framework. We apply this test to thermodynamics and derive a set of Leggett-Garg inequalities for the statistics of fluctuating work done on a quantum system unitarily driven in time. It is shown that these inequalities can be violated in a driven two-level system, thereby demonstrating that there exists no general macrorealistic description of quantum work. These violations are shown to emerge within the standard Two-Projective-Measurement scheme as well as for alternative definitions of fluctuating work that are based on weak measurement. Our results elucidate the influences of temporal correlations on work extraction in the quantum regime and highlight a key difference between quantum and classical thermodynamics.

Directed motion in a periodic potential of a quantum system coupled to a heat bath driven by a colored noise

2008 ◽  
Vol 78 (2) ◽  
Author(s):  
Satyabrata Bhattacharya ◽  
Pinaki Chaudhury ◽  
Sudip Chattopadhyay ◽  
Jyotipratim Ray Chaudhuri
Keyword(s):  
Quantum System ◽  
Colored Noise ◽  
Periodic Potential ◽  
Heat Bath ◽  
Directed Motion

scholarly journals From Quantum Probabilities to Quantum Amplitudes

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1389
Author(s):  
Sofia Martínez-Garaot ◽  
Marisa Pons ◽  
Dmitri Sokolovski
Keyword(s):  
Quantum System ◽  
General Problem ◽  
Weak Measurement ◽  
Level System ◽  
Transition Path ◽  
Initial State ◽  
Quantum Probabilities ◽  
Measurement Limit ◽  
Pauli Problem

The task of reconstructing the system’s state from the measurements results, known as the Pauli problem, usually requires repetition of two successive steps. Preparation in an initial state to be determined is followed by an accurate measurement of one of the several chosen operators in order to provide the necessary “Pauli data”. We consider a similar yet more general problem of recovering Feynman’s transition (path) amplitudes from the results of at least three consecutive measurements. The three-step histories of a pre- and post-selected quantum system are subjected to a type of interference not available to their two-step counterparts. We show that this interference can be exploited, and if the intermediate measurement is “fuzzy”, the path amplitudes can be successfully recovered. The simplest case of a two-level system is analysed in detail. The “weak measurement” limit and the usefulness of the path amplitudes are also discussed.

scholarly journals Quantum Photovoltaic Cells Driven by Photon Pulses

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 693
Author(s):  
Sangchul Oh ◽  
Jung Jun Park ◽  
Hyunchul Nha
Keyword(s):  
External Load ◽  
Power Efficiency ◽  
Thermal Contact ◽  
Heat Engine ◽  
Input Power ◽  
Thermodynamic Quantities ◽  
Level System ◽  
Cold Bath ◽  
Quantum Heat Engine ◽  
Photon Pulse

We investigate the quantum thermodynamics of two quantum systems, a two-level system and a four-level quantum photocell, each driven by photon pulses as a quantum heat engine. We set these systems to be in thermal contact only with a cold reservoir while the heat (energy) source, conventionally given from a hot thermal reservoir, is supplied by a sequence of photon pulses. The dynamics of each system is governed by a coherent interaction due to photon pulses in terms of the Jaynes-Cummings Hamiltonian together with the system-bath interaction described by the Lindblad master equation. We calculate the thermodynamic quantities for the two-level system and the quantum photocell including the change in system energy, the power delivered by photon pulses, the power output to an external load, the heat dissipated to a cold bath, and the entropy production. We thereby demonstrate how a quantum photocell in the cold bath can operate as a continuum quantum heat engine with a sequence of photon pulses continuously applied. We specifically introduce the power efficiency of the quantum photocell in terms of the ratio of output power delivered to an external load with current and voltage to the input power delivered by the photon pulse. Our study indicates a possibility that a quantum system driven by external fields can act as an efficient quantum heat engine under non-equilibrium thermodynamics.

Thermodynamics of Quantum Information Systems — Hamiltonian Description

2004 ◽  
Vol 11 (03) ◽  
pp. 205-217 ◽  
Author(s):  
Robert Alicki ◽  
Michał Horodecki ◽  
Paweł Horodecki ◽  
Ryszard Horodecki
Keyword(s):  
Quantum System ◽  
Weak Coupling ◽  
Heat Bath ◽  
Quantum Correlations ◽  
Weak Coupling Limit ◽  
Second Law ◽  
Hamiltonian Description ◽  
Landauer’S Principle ◽  
Thermodynamical Laws ◽  
The Cost

It is often claimed, that from a quantum system of d levels, and entropy S and heat bath of temperature T one can draw kT lnd–TS amount of work. However, the usual arguments basing on Szilard engine, are not fully rigorous. Here we prove the formula within Hamiltonian description of drawing work from a quantum system and a heat bath, at the cost of entropy of the system. We base on the derivation of thermodynamical laws and quantities in [10] within weak coupling limit. Our result provides fully physical scenario for extracting thermodynamical work form quantum correlations [4]. We also derive Landauer's principle as a consequence of the second law within the considered model.

Sign in / Sign up

Export Citation Format

Share Document