Quantum Otto heat engines on XYZ spin working medium with DM and KSEA interactions: Operating modes and efficiency at maximal work output

• URL: http://arxiv.org/abs/2301.07987v1
• Date: Thu, 19 Jan 2023 10:32:15 GMT
• Title: Quantum Otto heat engines on XYZ spin working medium with DM and KSEA interactions: Operating modes and efficiency at maximal work output
• Authors: Elena I. Kuznetsova, M. A. Yurischev and Saeed Haddadi
• Abstract summary: The efficiencies of engines at maximum power are estimated for various choices of model parameters. New additional points of local minima of the total work are revealed and the mechanism of their occurrence is analyzed.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: The magnetic Otto thermal machine based on a two-spin-1/2 XYZ working fluid in the presence of an inhomogeneous magnetic field and antisymmetric Dzyaloshinsky--Moriya (DM) and symmetric Kaplan--Shekhtman--Entin-Wohlman--Aharony (KSEA) interactions is considered. Its possible modes of operation are found and classified. The efficiencies of engines at maximum power are estimated for various choices of model parameters. There are cases when these efficiencies exceed the Novikov value. New additional points of local minima of the total work are revealed and the mechanism of their occurrence is analyzed.

Related papers

• Spin Squeezing with Magnetic Dipoles [37.93140485169168]
  Entanglement can improve the measurement precision of quantum sensors beyond the shot noise limit. We take advantage of the magnetic dipole-dipole interaction native to most neutral atoms to realize spin-squeezed states. We achieve 7.1 dB of metrologically useful squeezing using the finite-range spin exchange interactions in an erbium quantum gas microscope.
  arXiv  Detail & Related papers  (2024-11-11T18:42:13Z)
• Quantum machines using \mathrm{Cu}_{3}-like compounds modeled by Heisenberg antiferromagnetic in a triangular ring [0.0]
  magnetocaloric effect (MCE) is significant at low temperatures (around 1K) under a perpendicular magnetic field (sim5T) We analyze how MCE influences the Carnot machine, which operates as a heat engine or refrigerator when varying the external magnetic field. Our results indicate that enhanced MCE broadens the operating regions for these machines, with the Otto and Stirling machines primarily functioning as refrigerators and accelerators.
  arXiv  Detail & Related papers  (2024-06-03T14:04:01Z)
• A finite-time quantum Otto engine with tunnel coupled one-dimensional Bose gases [0.0]
  We study a finite-time quantum Otto engine cycle driven by inter-particle interactions in a weakly interacting Bose gas. We find that, unlike a uniform 1D Bose gas, a harmonically trapped quasicondensate cannot operate purely as a emphheat engine.
  arXiv  Detail & Related papers  (2024-04-25T09:54:21Z)
• Is Temperature Sample Efficient for Softmax Gaussian Mixture of Experts? [27.924615931679757]
  We explore the impacts of a dense-to-sparse gating mixture of experts (MoE) on the maximum likelihood estimation under the MoE. We propose using a novel activation dense-to-sparse gate, which routes the output of a linear layer to an activation function before delivering them to the softmax function.
  arXiv  Detail & Related papers  (2024-01-25T01:09:09Z)
• Work and efficiency fluctuations in a quantum Otto cycle with idle levels [0.0]
  We study the performance of a quantum Otto heat engine with two spins coupled by a Heisenberg interaction. We find that the relative fluctuations in work or efficiency remain large, implying that this microscopic engine is not very reliable as a source of work.
  arXiv  Detail & Related papers  (2023-12-19T17:28:54Z)
• Universal quantum Otto heat machine based on the Dicke model [0.0]
  We study a quantum Otto thermal machine where the working substance is composed of N identical qubits coupled to a single mode of a bosonic field. We show that it is possible to build a universal quantum heat machine (UQHM) that can function as an engine, refrigerator, heater or accelerator.
  arXiv  Detail & Related papers  (2023-08-13T02:27:17Z)
• Powerful ordered collective heat engines [58.720142291102135]
  We introduce a class of engines in which the regime of units operating synchronously can boost the performance. We show that the interplay between Ising-like interactions and a collective ordered regime is crucial to operate as a heat engine.
  arXiv  Detail & Related papers  (2023-01-16T20:14:19Z)
• Sensing of magnetic field effects in radical-pair reactions using a quantum sensor [50.591267188664666]
  Magnetic field effects (MFE) in certain chemical reactions have been well established in the last five decades. We employ elaborate and realistic models of radical-pairs, considering its coupling to the local spin environment and the sensor. For two model systems, we derive signals of MFE detectable even in the weak coupling regime between radical-pair and NV quantum sensor.
  arXiv  Detail & Related papers  (2022-09-28T12:56:15Z)
• Enhancing the performance of coupled quantum Otto thermal machines without entanglement and quantum correlations [0.0]
  Two- and three-coupled spin-$1/2$ Heisenberg $XXX$-chain. We show that only when the number of interacting spins is odd the system can work as a heat engine in the strong coupling regime. This model confirms the idea that entanglement and quantum correlations are not the reasons behind the advantages observed in efficiency, extracatable work, and COP.
  arXiv  Detail & Related papers  (2022-05-19T17:36:34Z)
• Quantum heat engines with complex working media, complete Otto cycles and heuristics [0.0]
  We examine the performance of a quasi-static quantum Otto engine based on two spins of arbitrary magnitudes. The study of complete Otto cycles inherent in the average cycle also yields interesting insights into the average performance.
  arXiv  Detail & Related papers  (2021-07-26T16:18:50Z)
• Collective effects on the performance and stability of quantum heat engines [62.997667081978825]
  Recent predictions for quantum-mechanical enhancements in the operation of small heat engines have raised renewed interest. One essential question is whether collective effects may help to carry enhancements over larger scales. We study how power, efficiency and constancy scale with the number of spins composing the engine.
  arXiv  Detail & Related papers  (2021-06-25T18:00:07Z)
• Maximal power for heat engines: role of asymmetric interaction times [110.83289076967895]
  We introduce the idea of adjusting the interaction time asymmetry in order to optimize the engine performance. Distinct optimization protocols are analyzed in the framework of thermodynamics.
  arXiv  Detail & Related papers  (2020-12-16T22:26:14Z)
• Spin Entanglement and Magnetic Competition via Long-range Interactions in Spinor Quantum Optical Lattices [62.997667081978825]
  We study the effects of cavity mediated long range magnetic interactions and optical lattices in ultracold matter. We find that global interactions modify the underlying magnetic character of the system while introducing competition scenarios. These allow new alternatives toward the design of robust mechanisms for quantum information purposes.
  arXiv  Detail & Related papers  (2020-11-16T08:03:44Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.