Dynamics of a small quantum system open to a bath with thermostat

• URL: http://arxiv.org/abs/2404.15568v1
• Date: Tue, 23 Apr 2024 23:45:56 GMT
• Title: Dynamics of a small quantum system open to a bath with thermostat
• Authors: Chulan Kwon, Ju-Yeon Gyhm,
• Abstract summary: We investigate dynamics of a small quantum system open to a bath with thermostat. We introduce another bath, called super bath, weakly coupled with the bath to provide it with thermostat. We find steady state does not depend on thermostat, but time-dependent state does, that agrees with common expectation.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We investigate dynamics of a small quantum system open to a bath with thermostat. We introduce another bath, called super bath, weakly coupled with the bath to provide it with thermostat, which has either the Lindblad or Redfield type. We treat the interaction between the system and bath via a rigorous perturbation theory. Due to the thermostat, the bath behaves dissipative and stochastic, for which the usual Born-Markov assumption is not needed. We consider a specific example of a harmonic oscillator system, and a photonic bath in a large container, and a super bath of the Caldeira-Legget oscillators distributed on the inner surface of the container. We use the $P$-representation for the total harmonic system. We derive the reduced time-evolution equation for the system by explicitly finding the correlation between the system and bath beyond the product state, that was not obtainable in the previous theory for the system and bath isolated from environment, and marginalizing bath degrees of freedom. Remarkably, the associated dynamic equation for the system density matrix is of the same form as the Redfield master equation with different coefficients depending on thermostat used. We find steady state does not depend on thermostat, but time-dependent state does, that agrees with common expectation. We expect to apply our theory to general systems. Unlike the usual quantum master equations, our reduced dynamics allows investigation for time-dependent protocols and non-equilibrium quantum stochastic dynamics will be investigated in future.

Related papers

• Thermodynamic Roles of Quantum Environments: From Heat Baths to Work Reservoirs [49.1574468325115]
  Environments in quantum thermodynamics usually take the role of heat baths. We show that within the same model, the environment can take three different thermodynamic roles. The exact role of the environment is determined by the strength and structure of the coupling.
  arXiv  Detail & Related papers  (2024-08-01T15:39:06Z)
• Pseudomode treatment of strong-coupling quantum thermodynamics [0.0]
  The evaluation of thermodynamic quantities in strong-coupling regimes requires a nonperturbative knowledge of the bath dynamics. We derive expressions for heat, work, and average system-bath interaction energy that only involve the autocorrelation function of the bath. We show in particular that this method allows for an efficient numerical evaluation of thermodynamic quantities.
  arXiv  Detail & Related papers  (2024-07-25T09:11:45Z)
• Unifying Collisional Models and the Monte Carlo Metropolis Method: Algorithms for Dynamics of Open Quantum Systems [0.0]
  Collisional models are a category of microscopic open quantum system models that have seen growing use in studying quantum thermalization. We demonstrate that, when each bath ancilla is prepared in a thermal state with a discrete spectrum that matches the energy eigenstate transitions of the system, the system dynamics generated by the collisional model framework are identical to those generated under the Metropolis algorithm.
  arXiv  Detail & Related papers  (2024-03-01T00:01:22Z)
• Thermal-bath effects in quantum quenches within quantum critical regimes [0.0]
  We address the out-of-equilibrium dynamics arising from quantum-quench protocols (instantaneous changes of the Hamiltonian parameters) in many-body systems.
  arXiv  Detail & Related papers  (2023-05-09T14:46:46Z)
• Floquet-heating-induced Bose condensation in a scar-like mode of an open driven optical-lattice system [62.997667081978825]
  We show that the interplay of bath-induced dissipation and controlled Floquet heating can give rise to non-equilibrium Bose condensation. Our predictions are based on a microscopic model that is solved using kinetic equations of motion derived from Floquet-Born-Markov theory.
  arXiv  Detail & Related papers  (2022-04-14T17:56:03Z)
• Fast Thermalization from the Eigenstate Thermalization Hypothesis [69.68937033275746]
  Eigenstate Thermalization Hypothesis (ETH) has played a major role in understanding thermodynamic phenomena in closed quantum systems. This paper establishes a rigorous link between ETH and fast thermalization to the global Gibbs state. Our results explain finite-time thermalization in chaotic open quantum systems.
  arXiv  Detail & Related papers  (2021-12-14T18:48:31Z)
• 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)
• Taking the temperature of a pure quantum state [55.41644538483948]
  Temperature is a deceptively simple concept that still raises deep questions at the forefront of quantum physics research. We propose a scheme to measure the temperature of such pure states through quantum interference.
  arXiv  Detail & Related papers  (2021-03-30T18:18:37Z)
• Nonequilibrium Quantum Free Energy and Effective Temperature, Generating Functional and Influence Action [0.0]
  A formal derivation is provided by way of the generating functional in terms of the coarse-grained effective action and the influence action. The nonequilibrium thermodynamic functions we find here obey the familiar relation $mathcalF_textscs(t)=mathcalU_textscs(t)- T_textsceff (t),mathcalS_vN(t)$ it at any and all moments of time in the system's fully nonequilibrium evolution history.
  arXiv  Detail & Related papers  (2020-11-20T16:01:11Z)
• Quantum systems correlated with a finite bath: nonequilibrium dynamics and thermodynamics [0.0]
  We derive a master equation that accounts for system-bath correlations and includes, at a coarse-grained level, a dynamically evolving bath. Our work paves the way for studying a variety of nanoscale quantum technologies including engines, refrigerators, or heat pumps.
  arXiv  Detail & Related papers  (2020-08-05T15:19:29Z)
• Out-of-equilibrium quantum thermodynamics in the Bloch sphere: temperature and internal entropy production [68.8204255655161]
  An explicit expression for the temperature of an open two-level quantum system is obtained. This temperature coincides with the environment temperature if the system reaches thermal equilibrium with a heat reservoir. We show that within this theoretical framework the total entropy production can be partitioned into two contributions.
  arXiv  Detail & Related papers  (2020-04-09T23:06:43Z)

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.