On Schr\"odingerist Quantum Thermodynamics

• URL: http://arxiv.org/abs/2208.07688v8
• Date: Sun, 8 Jan 2023 12:51:48 GMT
• Title: On Schr\"odingerist Quantum Thermodynamics
• Authors: Leonardo De Carlo and W. David Wick
• Abstract summary: We consider several models of magnets that can exhibit a phase transition to a low-temperature magnetized state. We show that the SQUIM with free boundary conditions and distinguishable spins" has no finite-temperature phase transition. A variant model with wavefunction energy" does have a phase transition to a magnetised state.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: From the point of view of Schr\"odingerism, a wavefunction-only philosophy, thermodynamics must be recast in terms of an ensemble of wavefunctions, rather than classical particle configurations or ``found" values of Copenaghen Quantum Mechanics. Recapitulating the historical sequence, we consider here several models of magnets that classically can exhibit a phase transition to a low-temperature magnetized state. We formulate wavefunction analogues including a ``Schr\"odingerist QUantum Ising Model" (SQUIM), a ``Schr\"odingerist Curie-Weiss Model" (SCWM), and others. We show that the SQUIM with free boundary conditions and distinguishable ``spins" has no finite-temperature phase transition, which we attribute to entropy swamping energy. The SCWM likewise, even assuming exchange symmetry in the wavefunction (in this case the analytical argument is not totally satisfactory and we helped ourself with a computer analysis). But a variant model with ``wavefunction energy" (introduced in prior communications about Schr\"odingerism and the Measurement Problem) does have a phase transition to a magnetised state. The three results together suggest that magnetization in large quantum spin chains appears if and only if we consider indistinguishable particles and for large $N$ we break the superposition principle blocking macroscopic dispersion by energy conservation. Our principle technique involves transforming the problem to one in probability theory, then applying results from Large Deviations, particularly the G\"artner-Ellis Theorem. Finally, we discuss Gibbs vs. Boltzmann/Einstein entropy in the choice of the quantum thermodynamic ensemble, as well as open problems. PhySH: quantum theory, quantum statistical mechanics, large deviation & rare event statistics.

Related papers

• Quantum decoherence from complex saddle points [0.0]
  Quantum decoherence is the effect that bridges quantum physics to classical physics. We present some first-principle calculations in the Caldeira-Leggett model. We also discuss how to extend our work to general models by Monte Carlo calculations.
  arXiv  Detail & Related papers  (2024-08-29T15:35:25Z)
• Quantumness and quantum to classical transition in the generalized Rabi model [17.03191662568079]
  We define the quantumness of a Hamiltonian by the free energy difference between its quantum and classical descriptions. We show that the Jaynes-Cummings and anti Jaynes-Cummings models exhibit greater quantumness than the Rabi model.
  arXiv  Detail & Related papers  (2023-11-12T18:24:36Z)
• Quantum Effects on the Synchronization Dynamics of the Kuramoto Model [62.997667081978825]
  We show that quantum fluctuations hinder the emergence of synchronization, albeit not entirely suppressing it. We derive an analytical expression for the critical coupling, highlighting its dependence on the model parameters.
  arXiv  Detail & Related papers  (2023-06-16T16:41:16Z)
• Independent-oscillator model and the quantum Langevin equation for an oscillator: A review [19.372542786476803]
  A derivation of the quantum Langevin equation is outlined based on the microscopic model of the heat bath. In the steady state, we analyze the quantum counterpart of energy equipartition theorem. The free energy, entropy, specific heat, and third law of thermodynamics are discussed for one-dimensional quantum Brownian motion.
  arXiv  Detail & Related papers  (2023-06-05T07:59:35Z)
• Demonstrating Quantum Microscopic Reversibility Using Coherent States of Light [58.8645797643406]
  We propose and experimentally test a quantum generalization of the microscopic reversibility when a quantum system interacts with a heat bath. We verify that the quantum modification for the principle of microscopic reversibility is critical in the low-temperature limit.
  arXiv  Detail & Related papers  (2022-05-26T00:25:29Z)
• Correspondence Between the Energy Equipartition Theorem in Classical Mechanics and its Phase-Space Formulation in Quantum Mechanics [62.997667081978825]
  In quantum mechanics, the energy per degree of freedom is not equally distributed. We show that in the high-temperature regime, the classical result is recovered.
  arXiv  Detail & Related papers  (2022-05-24T20:51:03Z)
• 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)
• 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)
• Strong Coupling Quantum Thermodynamics with Renormalized Hamiltonian and Temperature [2.542198147027801]
  We develop strong coupling quantum thermodynamics based on the solution of the exact master equation. We find that both the Hamiltonian and the temperature must be renormalized due to the system-reservoir couplings. With the renormalized Hamiltonian and temperature, the exact steady state of open quantum systems can be expressed as a standard Gibbs state.
  arXiv  Detail & Related papers  (2020-10-05T07:34:26Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)

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.