Efficiency gain and bidirectional operation of quantum engines with decoupled internal levels

• URL: http://arxiv.org/abs/2008.11694v3
• Date: Fri, 21 Jan 2022 19:42:01 GMT
• Title: Efficiency gain and bidirectional operation of quantum engines with decoupled internal levels
• Authors: Thiago R. de Oliveira, Daniel Jonathan
• Abstract summary: We present a mechanism for efficiency increase in quantum heat engines containing internal energy levels that do not couple to the external work sink. The gain is achieved by using these levels to channel heat in a direction opposite to the one dictated by the second law. A similar mechanism allows the engine to run in reverse and still produce useful work.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We present a mechanism for efficiency increase in quantum heat engines containing internal energy levels that do not couple to the external work sink. The gain is achieved by using these levels to channel heat in a direction opposite to the one dictated by the second law. No quantum coherence, quantum correlations or ergotropy are required. A similar mechanism allows the engine to run in reverse and still produce useful work. We illustrate these ideas using a simple quantum Otto cycle in a coupled-spin system. We find this engine also exhibits other counterintuitive phenomenology. For example, its efficiency may increase as the temperature difference between the heat baths decreases. Conversely, it may cease to operate if the hotter bath becomes too hot or the colder bath too cold.

Related papers

• Phonon-photon conversion as mechanism for cooling and coherence transfer [41.94295877935867]
  The energy of a movable wall of a cavity confining a quantum field can be converted into quanta of the field itself. We employ quantum thermodynamics to show that this phenomenon can be employed as a tool to cool down the wall. We show how to employ one laser drive to cool the entire system including the case when it is composed of other subsystems.
  arXiv  Detail & Related papers  (2023-12-15T14:42:16Z)
• Anisotropy-assisted thermodynamic advantage of a local-spin thermal machine [0.0]
  We study quantum Otto thermal machines with a two-spin working system coupled by anisotropic interaction. We show that the efficiency of such an engine can surpass the standard quantum Otto limit, along with maximum power, thanks to the anisotropy.
  arXiv  Detail & Related papers  (2023-09-09T11:05:28Z)
• Quantum field heat engine powered by phonon-photon interactions [58.720142291102135]
  We present a quantum heat engine based on a cavity with two oscillating mirrors. The engine performs an Otto cycle during which the walls and a field mode interact via a nonlinear Hamiltonian.
  arXiv  Detail & Related papers  (2023-05-10T20:27:15Z)
• Implementation of a two-stroke quantum heat engine with a collisional model [50.591267188664666]
  We put forth a quantum simulation of a stroboscopic two-stroke thermal engine in the IBMQ processor. The system consists of a quantum spin chain connected to two baths at their boundaries, prepared at different temperatures using the variational quantum thermalizer algorithm.
  arXiv  Detail & Related papers  (2022-03-25T16:55:08Z)
• The quantum Otto cycle in a superconducting cavity in the non-adiabatic regime [62.997667081978825]
  We analyze the efficiency of the quantum Otto cycle applied to a superconducting cavity. It is shown that, in a non-adiabatic regime, the efficiency of the quantum cycle is affected by the dynamical Casimir effect.
  arXiv  Detail & Related papers  (2021-11-30T11:47:33Z)
• Pulsed multireservoir engineering for a trapped ion with applications to state synthesis and quantum Otto cycles [68.8204255655161]
  Reservoir engineering is a remarkable task that takes dissipation and decoherence as tools rather than impediments. We develop a collisional model to implement reservoir engineering for the one-dimensional harmonic motion of a trapped ion. Having multiple internal levels, we show that multiple reservoirs can be engineered, allowing for more efficient synthesis of well-known non-classical states of motion.
  arXiv  Detail & Related papers  (2021-11-26T08:32:39Z)
• Quantum signatures in quadratic optomechanical heat engine with an atom in a tapered trap [0.0]
  We investigate how quantum signatures can emerge in a single atom heat engine consisting of an atom confined in a tapered trap. We model such a system using a quadratic optomechanical model and identify an effective Otto cycle in the system's dynamics.
  arXiv  Detail & Related papers  (2021-11-24T21:24:21Z)
• 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)
• Quantum Heat Engines with Carnot Efficiency at Maximum Power [0.0]
  We introduce quantum heat engines that deliver maximum power with Carnot efficiency in the one-shot finite-size regime. The engines operate in a one-step cycle by letting the working system simultaneously interact with hot and cold baths.
  arXiv  Detail & Related papers  (2021-06-02T14:34:38Z)
• Study of quantum Otto heat engine using driven-dissipative Schr\"{o}dinger equation [2.2559617939136505]
  We study the dynamics of the quantum Otto heat engine using the driven-dissipative Schr"odinger equation. We propose a new quantum engine working in a single reservoir to convert the pump energy into mechanical work.
  arXiv  Detail & Related papers  (2020-10-10T00:56:23Z)
• An endoreversible quantum heat engine driven by atomic collisions [0.0]
  We realize an endoreversible quantum Otto cycle in the large quasi-spin states of Cesium impurities immersed in an ultracold Rubidium bath. We employ quantum control over both machine and bath to suppress internal dissipation and regulate the direction of heat transfer. We optimize the performance as well as the stability of the quantum engine, achieving high efficiency, large power output and small power output fluctuations.
  arXiv  Detail & Related papers  (2020-09-23T06:32:04Z)

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.