Quantum Level-Crossing Induced by Anisotropy in Spin-1 Heisenberg Dimers: Applications to Quantum Stirling Engines

TL;DR

This paper investigates how anisotropy-induced quantum level crossings in spin-1 Heisenberg dimers can optimize the performance and efficiency of quantum Stirling heat engines, revealing key degeneracy points that enhance work output.

Contribution

It introduces the role of anisotropic spin-1 Heisenberg dimers and their energy degeneracies in improving quantum heat engine efficiency, advancing quantum thermodynamics understanding.

Findings

Degenerate points significantly boost engine efficiency.

Higher work output at degeneracy points.

Enhanced stability of the quantum Stirling engine.

Abstract

This work explores the thermodynamic performance of a quantum Stirling heat engine implemented with an anisotropic spin-1 Heisenberg dimer as the working medium. Using the Hamiltonian of the system, we analyze the interplay of anisotropy, magnetic field, and exchange interactions and their influence on the energy spectrum and the quantum level crossing. Our results reveal that double-degenerate point (DDP) and a triple-degenerate point (TDP) play pivotal roles in shaping the operational regimes and efficiency of the quantum Stirling engine. At those points, the Carnot efficiency reaches higher work output and enhanced stability, making it a robust candidate for optimal thermodynamic performance. These findings highlight the potential of anisotropic spin systems as viable platforms for quantum heat engines and contribute to advancing the field of quantum thermodynamics.