Optimizing power and efficiency of a single spin heat engine

Fuente: arXiv
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Main Authors: Majumdar, Rita, Chatterjee, Monojit, Marathe, Rahul
Format: Preprint
Published: 2024
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author Majumdar, Rita
Chatterjee, Monojit
Marathe, Rahul
author_facet Majumdar, Rita
Chatterjee, Monojit
Marathe, Rahul
contents We study the behavior of a single spin in the presence of a time-varying magnetic field utilizing Glauber dynamics. We engineer the system to function as an engine by changing the magnetic field according to specific protocols. Subsequently, we analyze the engine's performance using various protocols and stochastic thermodynamics to compute average values of crucial quantities for quantifying engine performance. In the longtime limit of the engine cycle, we derive exact analytical expressions for work, heat, and efficiency in terms of a generalized protocol. We then analyze the model in terms of optimization of efficiency and power. Additionally, we use different protocols and employ a gradient descent algorithm to best fit those to obtain optimal efficiency and then optimal power for a finite cycle time. All the protocols converge to the piece-wise constant protocol during efficiency optimization. We then explore a more general approach using the variational principle to determine the optimal protocols for optimizing power and efficiency. During the optimization process for both power and efficiency, the net entropy production decreases, which enhances the engine's performance. This approach demonstrates the superior optimization of efficiency and power in this system compared to the gradient descent algorithm.
format Preprint
id arxiv_https___arxiv_org_abs_2412_09802
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Optimizing power and efficiency of a single spin heat engine
Majumdar, Rita
Chatterjee, Monojit
Marathe, Rahul
Statistical Mechanics
We study the behavior of a single spin in the presence of a time-varying magnetic field utilizing Glauber dynamics. We engineer the system to function as an engine by changing the magnetic field according to specific protocols. Subsequently, we analyze the engine's performance using various protocols and stochastic thermodynamics to compute average values of crucial quantities for quantifying engine performance. In the longtime limit of the engine cycle, we derive exact analytical expressions for work, heat, and efficiency in terms of a generalized protocol. We then analyze the model in terms of optimization of efficiency and power. Additionally, we use different protocols and employ a gradient descent algorithm to best fit those to obtain optimal efficiency and then optimal power for a finite cycle time. All the protocols converge to the piece-wise constant protocol during efficiency optimization. We then explore a more general approach using the variational principle to determine the optimal protocols for optimizing power and efficiency. During the optimization process for both power and efficiency, the net entropy production decreases, which enhances the engine's performance. This approach demonstrates the superior optimization of efficiency and power in this system compared to the gradient descent algorithm.
title Optimizing power and efficiency of a single spin heat engine
topic Statistical Mechanics
url https://arxiv.org/abs/2412.09802