scholarly journals Entropy Exchange and Thermodynamic Properties of the Single Ion Cooling Process

Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 650
Author(s):  
Jian-Guo Miao ◽  
Chun-Wang Wu ◽  
Wei Wu ◽  
Ping-Xing Chen
Keyword(s):  
Thermodynamic Properties ◽  
Heat Engine ◽  
Entropy Change ◽  
Quantum Thermodynamics ◽  
Cooling Process ◽  
Cooling Cycle ◽  
Heat Engines ◽  
Quantum Heat Engine ◽  
Ion Cooling ◽  
Complete Quantum

A complete quantum cooling cycle may be a useful platform for studying quantum thermodynamics just as the quantum heat engine does. Entropy change is an important feature which can help us to investigate the thermodynamic properties of the single ion cooling process. Here, we analyze the entropy change of the ion and laser field in the single ion cooling cycle by generalizing the idea in Reference (Phys. Rev. Lett. 2015, 114, 043002) to a single ion system. Thermodynamic properties of the single ion cooling process are discussed and it is shown that the Second and Third Laws of Thermodynamics are still strictly held in the quantum cooling process. Our results suggest that quantum cooling cycles are also candidates for the investigation on quantum thermodynamics besides quantum heat engines.

Quantum Optomechanics Thermodynamics and Heat Engines

2020 ◽  
pp. 399-450
Author(s):  
Pierre Meystre
Keyword(s):  
Thermal Noise ◽  
Heat Engine ◽  
Experimental Tests ◽  
Heat Pumps ◽  
Quantum Mechanical ◽  
Quantum Thermodynamics ◽  
Heat Engines ◽  
Quantum Heat Engine ◽  
Quantum Optomechanics ◽  
Thermodynamic Processes

This chapter addresses topics in quantum thermodynamics, where optomechanics may contribute attractive experimental tests and additional understanding. Quantum thermodynamics can be defined as the study of thermodynamics when quantum mechanical noise coexists with thermal noise and has a significant impact on the dynamics. This chapter focuses on the example of an optomechanical quantum heat engine (QHE). Section 11.2 reviews some questions about quantum work. Section 11.3 then outlines the steps leading to the formulation of continuous measurements in terms of stochastic Schrödinger equations. Section 11.4 reviews the main characteristics of QHE, comparing thermodynamic processes and engine cycles in the classical and quantum regimes. The opportunities offered by quasiparticles in the operation of QHE justify reviewing their properties in some detail (section 11.5), before introducing the optomechanical QHE system (section 11.6). Section 11.7 discusses the properties of the engine, and section 11.8 expands the discussion to polariton based quantum heat pumps.

scholarly journals Relativistic quantum heat engine from uncertainty relation standpoint

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pritam Chattopadhyay ◽  
Goutam Paul
Keyword(s):  
Uncertainty Relation ◽  
Relativistic Quantum ◽  
Heat Engine ◽  
Potential Well ◽  
Relativistic Case ◽  
Heat Engines ◽  
Quantum Heat Engine ◽  
Thermodynamic Variables ◽  
The One ◽  
Work Done

AbstractEstablished heat engines in quantum regime can be modeled with various quantum systems as working substances. For example, in the non-relativistic case, we can model the heat engine using infinite potential well as a working substance to evaluate the efficiency and work done of the engine. Here, we propose quantum heat engine with a relativistic particle confined in the one-dimensional potential well as working substance. The cycle comprises of two isothermal processes and two potential well processes of equal width, which forms the quantum counterpart of the known isochoric process in classical nature. For a concrete interpretation about the relation between the quantum observables with the physically measurable parameters (like the efficiency and work done), we develop a link between the thermodynamic variables and the uncertainty relation. We have used this model to explore the work extraction and the efficiency of the heat engine for a relativistic case from the standpoint of uncertainty relation, where the incompatible observables are the position and the momentum operators. We are able to determine the bounds (the upper and the lower bounds) of the efficiency of the heat engine through the thermal uncertainty relation.

scholarly journals Bound on Efficiency of Heat Engine from Uncertainty Relation Viewpoint

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 439
Author(s):  
Pritam Chattopadhyay ◽  
Ayan Mitra ◽  
Goutam Paul ◽  
Vasilios Zarikas
Keyword(s):  
Uncertainty Relation ◽  
Heat Engine ◽  
Upper And Lower Bounds ◽  
Engine Model ◽  
Heat Engines ◽  
Quantum Heat Engine ◽  
Quantum Observables ◽  
Thermodynamic Variables ◽  
Work Done ◽  
The Relationship

Quantum cycles in established heat engines can be modeled with various quantum systems as working substances. For example, a heat engine can be modeled with an infinite potential well as the working substance to determine the efficiency and work done. However, in this method, the relationship between the quantum observables and the physically measurable parameters—i.e., the efficiency and work done—is not well understood from the quantum mechanics approach. A detailed analysis is needed to link the thermodynamic variables (on which the efficiency and work done depends) with the uncertainty principle for better understanding. Here, we present the connection of the sum uncertainty relation of position and momentum operators with thermodynamic variables in the quantum heat engine model. We are able to determine the upper and lower bounds on the efficiency of the heat engine through the uncertainty relation.

scholarly journals Space-fractional quantum heat engine based on level degeneracy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ekrem Aydiner
Keyword(s):  
Heat Engine ◽  
Tuning Parameter ◽  
Potential Well ◽  
Fractional Quantum ◽  
Heat Engines ◽  
Quantum Heat Engine ◽  
Large Size ◽  
Level Degeneracy ◽  
Infinite Potential Well ◽  
Quantum Heat Engines

AbstractIn order to examine the work and efficiency of the space-fractional quantum heat engine, we consider a model of the space-fractional quantum heat engine which has a Stirling-like cycle with a single particle under infinite potential well as an example. We numerically compute the work and efficiency for various fractional exponents. We show the work and the efficiency of the engine depending on the length of the potential well and fractional exponent of the engine. Furthermore, we show that fractional exponent plays a substantial role in the operating range of the quantum heat engine. Thus, we conclude that the fractional parameter can be used as a tuning parameter to obtain positive work and efficiency for the large size of the quantum heat engine. Additionally, the numerical results and model imply that the size of the engine can be enlarged in the nano-scale by using fractional deformations. As a result, in this study, we have not only shown that fractional deformations in space play an important role on the work and efficiency of the quantum heat engines but also introduced the concept of fractional quantum heat engines to the literature.

scholarly journals Information, Entropy Decrease and Simulations of Astrophysical Evolutions

2021 ◽  
Vol 5 (2) ◽  
pp. 1-11
Author(s):  
Chang YF
Keyword(s):  
Information Systems ◽  
Theoretical Result ◽  
Information Entropy ◽  
Heat Engine ◽  
Simulation Models ◽  
Quantum Thermodynamics ◽  
Entropy Increase ◽  
Quantum Heat Engine ◽  
The Universe ◽  
Great Development

Entropy is a great development in science. We proposed that entropy decrease due to internal interactions in the isolated system is possible. We define the entangled scale, which mainly involves the number n and entangled degree. Since coherence, entanglement and correlation are all internal interactions in information systems, we discuss quantitatively entropy decrease along coherence, and entropy increase only for incoherence. From beginning quantum heat engine, we must systematically study quantum thermodynamics. Based on some astrophysical simulation models, they shown that the universe evolves from disorder to structures, which correspond to entropy decrease. This is consistence with theoretical result. The simulation must be an isolated system only using internal gravitational interactions.

scholarly journals Concepts of work in autonomous quantum heat engines

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 195 ◽  
Author(s):  
Wolfgang Niedenzu ◽  
Marcus Huber ◽  
Erez Boukobza
Keyword(s):  
Free Energy ◽  
Classical Limit ◽  
Entropy Change ◽  
Quantum Thermodynamics ◽  
Engine Efficiency ◽  
Heat Engines ◽  
Quantum Domain ◽  
Quantum Heat Engines ◽  
Non Equilibrium

One of the fundamental questions in quantum thermodynamics concerns the decomposition of energetic changes into heat and work. Contrary to classical engines, the entropy change of the piston cannot be neglected in the quantum domain. As a consequence, different concepts of work arise, depending on the desired task and the implied capabilities of the agent using the work generated by the engine. Each work quantifier---from ergotropy to non-equilibrium free energy---has well defined operational interpretations. We analyse these work quantifiers for a heat-pumped three-level maser and derive the respective engine efficiencies. In the classical limit of strong maser intensities the engine efficiency converges towards the Scovil--Schulz-DuBois maser efficiency, irrespective of the work quantifier.

scholarly journals Bound on Efficiency of Heat Engine From Uncertainty Relation Viewpoint

2021 ◽  
Author(s):  
Ayan Mitra ◽  
Pritam Chattapadhyay ◽  
Goutam Paul ◽  
Vasilios Zarikas
Keyword(s):  
Uncertainty Relation ◽  
Heat Engine ◽  
Upper And Lower Bounds ◽  
Engine Model ◽  
Heat Engines ◽  
Quantum Heat Engine ◽  
Quantum Observables ◽  
Thermodynamic Variables ◽  
Work Done ◽  
The Relationship

Abstract Quantum cycles in established heat engines can be modeled with various quantum systems as working substances. As for example, heat engine can be modeled with an infinite potential well as the working substance to determine the efficiency and work done. However, in this method, the relationship between the quantum observables and the physically measurable parameters, i.e., the efficiency and work done is not well understood from the quantum mechanics approach. A detailed analysis is needed to link the thermodynamical variables (on which the efficiency and work done depends) with the uncertainty principle for better understanding. Here, we present the connection of sum uncertainty relation of position and momentum operators with thermodynamic variables in the quantum heat engine model. We are able to determine the upper and lower bounds on the efficiency of the heat engine through uncertainty relation.

scholarly journals Modeling and Performance Optimization of an Irreversible Two-Stage Combined Thermal Brownian Heat Engine

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 419
Author(s):  
Congzheng Qi ◽  
Zemin Ding ◽  
Lingen Chen ◽  
Yanlin Ge ◽  
Huijun Feng
Keyword(s):  
Power Output ◽  
Performance Optimization ◽  
External Load ◽  
Thermal Contact ◽  
Heat Engine ◽  
Design Parameters ◽  
Load Effect ◽  
Heat Engines ◽  
Heat Leakage ◽  
Steady Current

Based on finite time thermodynamics, an irreversible combined thermal Brownian heat engine model is established in this paper. The model consists of two thermal Brownian heat engines which are operating in tandem with thermal contact with three heat reservoirs. The rates of heat transfer are finite between the heat engine and the reservoir. Considering the heat leakage and the losses caused by kinetic energy change of particles, the formulas of steady current, power output and efficiency are derived. The power output and efficiency of combined heat engine are smaller than that of single heat engine operating between reservoirs with same temperatures. When the potential filed is free from external load, the effects of asymmetry of the potential, barrier height and heat leakage on the performance of the combined heat engine are analyzed. When the potential field is free from external load, the effects of basic design parameters on the performance of the combined heat engine are analyzed. The optimal power and efficiency are obtained by optimizing the barrier heights of two heat engines. The optimal working regions are obtained. There is optimal temperature ratio which maximize the overall power output or efficiency. When the potential filed is subjected to external load, effect of external load is analyzed. The steady current decreases versus external load; the power output and efficiency are monotonically increasing versus external load.

scholarly journals Learning the best nanoscale heat engines through evolving network topology

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuto Ashida ◽  
Takahiro Sagawa
Keyword(s):  
Network Topology ◽  
Heat Engine ◽  
Search Space ◽  
Single Electron ◽  
Thermodynamic Efficiency ◽  
Full Potential ◽  
Thermal Systems ◽  
Nanoscale Systems ◽  
Heat Engines ◽  
Many Body Interactions

AbstractThe quest to identify the best heat engine has been at the center of science and technology. Considerable studies have so far revealed the potentials of nanoscale thermal machines to yield an enhanced thermodynamic efficiency in noninteracting regimes. However, the full benefit of many-body interactions is yet to be investigated; identifying the optimal interaction is a hard problem due to combinatorial explosion of the search space, which makes brute-force searches infeasible. We tackle this problem with developing a framework for reinforcement learning of network topology in interacting thermal systems. We find that the maximum possible values of the figure of merit and the power factor can be significantly enhanced by electron-electron interactions under nondegenerate single-electron levels with which, in the absence of interactions, the thermoelectric performance is quite low in general. This allows for an alternative strategy to design the best heat engines by optimizing interactions instead of single-electron levels. The versatility of the developed framework allows one to identify full potential of a broad range of nanoscale systems in terms of multiple objectives.

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