scholarly journals First and Second Law of Quantum Thermodynamics: A Consistent Derivation Based on a Microscopic Definition of Entropy

PRX Quantum ◽  
2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Philipp Strasberg ◽  
Andreas Winter
Keyword(s):  
Second Law ◽  
Quantum Thermodynamics ◽  
Definition Of

scholarly journals Quantum Thermodynamics in the Refined Weak Coupling Limit

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 725 ◽  
Author(s):  
Ángel Rivas
Keyword(s):  
System Dynamics ◽  
Internal Energy ◽  
Weak Coupling ◽  
Weak Coupling Limit ◽  
Second Law ◽  
Quantum Thermodynamics ◽  
Thermodynamic Framework ◽  
Definition Of

We present a thermodynamic framework for the refined weak coupling limit. In this limit, the interaction between system and environment is weak, but not negligible. As a result, the system dynamics becomes non-Markovian breaking divisibility conditions. Nevertheless, we propose a derivation of the first and second law just in terms of the reduced system dynamics. To this end, we extend the refined weak coupling limit for allowing slowly-varying external drivings and reconsider the definition of internal energy due to the non-negligible interaction.

Reactions in solution

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Phase Equilibria ◽  
Gas Phase ◽  
First Principles ◽  
Unique Feature ◽  
Life Sciences ◽  
Equilibrium Mixture ◽  
Second Law ◽  
Ideal Solution ◽  
Coupled Reactions ◽  
Definition Of

Another key chapter, examining reactions in solution. Starting with the definition of an ideal solution, and then introducing Raoult’s law and Henry’s law, this chapter then draws on the results of Chapter 14 (gas phase equilibria) to derive the corresponding results for equilibria in an ideal solution. A unique feature of this chapter is the analysis of coupled reactions, once again using first principles to show how the coupling of an endergonic reaction to a suitable exergonic reaction results in an equilibrium mixture in which the products of the endergonic reaction are present in much higher quantity. This demonstrates how coupled reactions can cause entropy-reducing events to take place without breaking the Second Law, so setting the scene for the future chapters on applications of thermodynamics to the life sciences, especially chapter 24 on bioenergetics.

scholarly journals From the GKLS Equation to the Theory of Solar and Fuel Cells

2017 ◽  
Vol 24 (03) ◽  
pp. 1740007 ◽  
Author(s):  
R. Alicki
Keyword(s):  
Fuel Cells ◽  
Quantum Information ◽  
Open Systems ◽  
Operational Definition ◽  
Quantum Model ◽  
Quantum Thermodynamics ◽  
Quantum Open Systems ◽  
Sound Theory ◽  
Wide Range ◽  
Definition Of

The mathematically sound theory of quantum open systems, formulated in the ’70s and highlighted by the discovery of Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) equation, found a wide range of applications in various branches of physics and chemistry, notably in the field of quantum information and quantum thermodynamics. However, it took 40 years before this formalism has been applied to explain correctly the operation principles of long existing energy transducers like photovoltaic, thermoelectric and fuel cells. This long path is briefly reviewed from the author’s perspective. Finally, the new, fully quantum model of chemical engine based on GKLS equation and applicable to fuel cells or replicators is outlined. The model illustrates the difficulty with an entirely quantum operational definition of work, comparable to the problem of quantum measurement.

Identical thermodynamical processes and the generalization of the Clausius inequality

2008 ◽  
Vol 86 (2) ◽  
pp. 369-377 ◽  
Author(s):  
J Anacleto ◽  
J M Ferreira ◽  
A Anacleto
Keyword(s):  
Second Law ◽  
Definition Of ◽  
Thermodynamical Processes ◽  
Clausius Inequality

We stress the advantages of heat and work reservoirs in the formalism of Thermodynamics and using an illustrative example show the need to reformulate the concepts of heat and work to avoid inconsistencies, namely, with regard to the Second Law. To deal with this problem, we use the concept of identical thermodynamical processes and obtain the condition for two such processes to be identical even when the system neighbourhood as a whole cannot be treated as a reservoir. The aforementioned concept is then applied to obtain a standardized definition of heat and work as well as a generalization of the well-known Clausius inequality. Finally, we return to the example given earlier to corroborate the effectiveness of our results.PACS Nos.: 05.70.–a, 44.90.+c, 65.40.Gr

scholarly journals Diffusive Bejan number and second law of thermodynamics toward a new dimensionless formulation of fluid dynamics laws

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 4005-4022 ◽  
Author(s):  
Michele Trancossi ◽  
Jose Pascoa
Keyword(s):  
Fluid Dynamics ◽  
Entropy Generation ◽  
Fluid Dynamic ◽  
Second Law Of Thermodynamics ◽  
Integral Form ◽  
Second Law ◽  
Bejan Number ◽  
Definition Of ◽  
New Formulation ◽  
Dimensionless Formulation

In a recent paper, Liversage and Trancossi have defined a new formulation of drag as a function of the dimensionless Bejan and Reynolds numbers. Further analysis of this hypothesis has permitted to obtain a new dimensionless formulation of the fundamental equations of fluid dynamics in their integral form. The resulting equations have been deeply discussed for the thermodynamic definition of Bejan number evidencing that the proposed formulation allows solving fluid dynamic problems in terms of entropy generation, allowing an effective optimization of design in terms of the Second law of thermodynamics. Some samples are discussed evidencing how the new formulation can support the generation of an optimized configuration of fluidic devices and that the optimized configurations allow minimizing the entropy generation.

scholarly journals Classical Mechanics as a Fundamental Law of Quantum Mechanics

2020 ◽  
Author(s):  
Yehuda Roth
Keyword(s):  
Hilbert Space ◽  
Quantum Mechanics ◽  
Classical Mechanics ◽  
Second Law ◽  
Operator Form ◽  
Fundamental Law ◽  
Third Law ◽  
Definition Of ◽  
Force Operator ◽  
Physical Quantities

n our previous paper, we showed that the so-called quantum entanglement also exists in classical mechanics. The inability to measure this classical entanglement was rationalized with the definition of a classical observer which collapses all entanglement into distinguishable states. It was shown that evidence for this primary coherence is Newton’s third law. However, in reformulating a "classical entanglement theory" we assumed the existence of Newton’s second law as an operator form where a force operator was introduced through a Hilbert space of force states. In this paper, we derive all related physical quantities and laws from basic quantum principles. We not only define a force operator but also derive the classical mechanic's laws and prove the necessity of entanglement to obtain Newton’s third law.

Quantum Thermodynamics for the Modeling of Hydrogen Storage on a Carbon Nanotube

2008 ◽  
Author(s):  
Michael R. von Spakovsky ◽  
Charles E. Smith ◽  
Vittorio Verda
Keyword(s):  
Quantum Mechanics ◽  
Carbon Nanotube ◽  
Carbon Atom ◽  
Stable Equilibrium ◽  
Equation Of Motion ◽  
Second Law ◽  
Quantum Thermodynamics ◽  
Thermodynamic State ◽  
Hydrogen Molecules ◽  
Non Equilibrium

A typical approach for modeling systems at a nanoscale in states of non-equilibrium undergoing an irreversible process is to use an ad hoc mixture of molecular dynamics (linear and nonlinear), i.e. classical mechanics, coupled to assumptions of stable equilibrium which allow one via analogy to incorporate equilibrium thermodynamic state information such as temperature and pressure into the modeling process. However, such an approach cannot describe the actual thermodynamic evolution in state which occurs in these systems since the equation of motion used (Newton’s second law) can only describe the evolution in state from one mechanical state to another. To capture the actual thermodynamic evolution, a more general equation of motion is needed. Such an equation has been proposed, i.e. the Beretta equation of motion, as part of a general theory, which unifies (not simply bridges as is the case in statistical thermodynamics) quantum mechanics and thermodynamics. It is called the unified quantum theory of mechanics and thermodynamics or quantum thermodynamics. This equation, which strictly satisfies all of the implications of the laws of thermodynamics, including the second law, as well as of quantum mechanics, describes the thermodynamic evolution in state of a system in non-equilibrium regardless of whether or not the system is in a state far from or close to stable equilibrium. This theory and its dynamical postulate are used here to model the storage of hydrogen in an isolated box modeled in 1D and 2D with a carbon atom at one end of the box in 1D and a carbon nanotube in the middle of the box in 2D. The system is prepared in a state with the hydrogen molecules initially far from stable equilibrium, after which the system is allowed to relax (evolve) to a state of stable equilibrium. The so-called energy eigenvalue problem is used to determine the energy eigenlevels and eigenstates of the system, while the nonlinear Beretta equation of motion is used to determine the evolution of the thermodynamic state of the system as well as the spatial distributions of the hydrogen molecules in time. The results of our initial simulations show in detail the trajectory of the state of the system as the hydrogen molecules, which are initially arranged to be far from the carbon atom or the carbon nanotube, are seen to spread out in the container and eventually become more concentrated near the carbon atom or atoms.

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