Quantum evolution of mixed states and performance of quantum heat engines

• URL: http://arxiv.org/abs/2412.10472v1
• Date: Thu, 12 Dec 2024 23:40:20 GMT
• Title: Quantum evolution of mixed states and performance of quantum heat engines
• Authors: Anatoly A. Svidzinsky, Wenzhuo Zhang,
• Abstract summary: We introduce a technique for calculation the density operator time evolution along the lines of Heisenberg representation of quantum mechanics. We show that such systems exhibit interesting quantum dynamics in which oscillators swap their thermal states due to entanglement induced in the process of energy exchange and yield noise induced coherence. Our results deepen understanding of quantum evolution of mixed states which could be useful to design quantum machines with a better performance.
• Score: 0.0
• License:
• Abstract: We introduce a technique for calculation the density operator time evolution along the lines of Heisenberg representation of quantum mechanics. Using this technique, we find the exact solution for the evolution of two and three coupled harmonic oscillators initially prepared in thermal states at different temperatures. We show that such systems exhibit interesting quantum dynamics in which oscillators swap their thermal states due to entanglement induced in the process of energy exchange and yield noise induced coherence. A photonic quantum heat engine (QHE) composed of two optical cavities can be modeled as coupled harmonic oscillators with time-dependent frequencies. Photons in the cavities become entangled during the engine operation. We show that the work done by such an engine is maximum if at the end of the cycle the oscillators swap numbers of excitations which can be achieved when the engine operates under the condition of parametric resonance. We also show that Carnot formula yields limiting efficiency for QHEs under general assumptions. Our results deepen understanding of quantum evolution of mixed states which could be useful to design quantum machines with a better performance.

Related papers

• Exploring the role of criticality in the quantum Otto cycle fueled by the anisotropic quantum Rabi-Stark model [0.0]
  Quantum heat machines, encompassing heat engines, refrigerators, heaters, and accelerators, represent the forefront of quantum thermodynamics. This paper investigates a quantum Otto engine operating in both ideal and finite-time scenarios. By focusing on quantum heat engines, our study reveals that these phase transitions critically modulate the efficiency and power of AQRSM-based engines.
  arXiv  Detail & Related papers  (2024-07-12T06:36:57Z)
• Thermalization and Criticality on an Analog-Digital Quantum Simulator [133.58336306417294]
  We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions. We digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization.
  arXiv  Detail & Related papers  (2024-05-27T17:40:39Z)
• Autonomous Quantum Heat Engine Based on Non-Markovian Dynamics of an Optomechanical Hamiltonian [0.0]
  We build an analytical and a non-Markovian quasiclassical model for this quantum heat engine. This proposal heralds the in-depth studies of quantum heat engines in the non-Markovian regime.
  arXiv  Detail & Related papers  (2024-03-27T12:45:12Z)
• Amplification of quantum transfer and quantum ratchet [56.47577824219207]
  We study a model of amplification of quantum transfer and making it directed which we call the quantum ratchet model. The ratchet effect is achieved in the quantum control model with dissipation and sink, where the Hamiltonian depends on vibrations in the energy difference synchronized with transitions between energy levels. Amplitude and frequency of the oscillating vibron together with the dephasing rate are the parameters of the quantum ratchet which determine its efficiency.
  arXiv  Detail & Related papers  (2023-12-31T14:04:43Z)
• 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)
• Hamiltonian Simulation of Quantum Beats in Radical Pairs Undergoing Thermal Relaxation on Near-term Quantum Computers [0.0]
  Quantum dynamics of the radical pair mechanism is a major driving force in quantum biology, materials science, and spin chemistry. We take advantage of quantum computers to simulate the Hamiltonian evolution and thermal relaxation of two radical pair systems undergoing the quantum-beat phenomena.
  arXiv  Detail & Related papers  (2022-08-22T07:29:25Z)
• 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)
• Information Scrambling in Computationally Complex Quantum Circuits [56.22772134614514]
  We experimentally investigate the dynamics of quantum scrambling on a 53-qubit quantum processor. We show that while operator spreading is captured by an efficient classical model, operator entanglement requires exponentially scaled computational resources to simulate.
  arXiv  Detail & Related papers  (2021-01-21T22:18:49Z)
• Evolution of a Non-Hermitian Quantum Single-Molecule Junction at Constant Temperature [62.997667081978825]
  We present a theory for describing non-Hermitian quantum systems embedded in constant-temperature environments. We find that the combined action of probability losses and thermal fluctuations assists quantum transport through the molecular junction.
  arXiv  Detail & Related papers  (2021-01-21T14:33:34Z)
• The efficiency of simple Quantum Engine Stirling and Ericsson cycle [0.0]
  The quantum engine cycle serves as an analogous representation of the macroscopic nature of heat engines and the quantum regime of thermal devices composed of a single element. The efficiency of quantum engines is derived, which is found to be analogous to classical thermodynamic engines.
  arXiv  Detail & Related papers  (2020-10-04T13:22:52Z)

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.