Thermal Time and Irreversibility from Non-Commuting Observables in Accelerated Quantum Systems

• URL: http://arxiv.org/abs/2604.08349v1
• Date: Thu, 09 Apr 2026 15:17:39 GMT
• Title: Thermal Time and Irreversibility from Non-Commuting Observables in Accelerated Quantum Systems
• Abstract summary: We show that distinguishability arises when the state satisfies the Kubo--Martin--Schwinger (KMS) condition and the detector couples through non-commuting observables.<n>We consider uniformly accelerated two-level detectors interacting with a quantum field in the Minkowski vacuum.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We investigate when temporal ordering becomes operationally meaningful in relativistic quantum field theory using localized detector models. A time parameter alone does not ensure that different sequences of operations are physically distinguishable. We show that distinguishability arises when the state satisfies the Kubo--Martin--Schwinger (KMS) condition and the detector couples through non-commuting observables. We consider uniformly accelerated two-level detectors interacting with a quantum field in the Minkowski vacuum. The restriction of the vacuum to the detector trajectory induces a thermal response characterized by the Unruh temperature and the Tolman profile. For sequential couplings through distinct observables, the reduced detector state depends on the ordering of interactions already at second order, with a dependence controlled by the KMS parameter. This asymmetry is quantified using quantum relative entropy. In a minimal model, the relevant states form a family of non-commuting Gibbs states with identical spectra and different generators, yielding a closed-form expression depending only on the dimensionless combination of temperature and detector energy scale.

Related papers

• Identifying quantum coherence in quantum annealers [37.067444579637076]
  We use many-body coherent oscillations (MBCO) as a diagnostic for the identification of system-wide coherence in analog quantum simulators.<n>This work gives a general roadmap for the search for quantum coherence in noisy, large-scale quantum platforms.
  arXiv  Detail & Related papers  (2026-02-24T20:39:41Z)
• Quantum Mpemba-like effect in Unruh thermalization [18.536642197518287]
  We revisit the thermal nature of the Unruh effect within a quantum thermodynamic framework.<n>For a Unruh-deWitt detector in $n$-dimensional Minkowski spacetime, we demonstrate that its irreversible thermalization to a Gibbs equilibrium state follows distinct trajectories.
  arXiv  Detail & Related papers  (2025-09-06T15:56:30Z)
• Time Symmetry, Retrocausality, and Emergent Collapse: The Tlalpan Interpretation of Quantum Mechanics [51.56484100374058]
  The Tlalpan Interpretation (QTI) proposes that the wavefunction collapse is not a primitive, axiomatic rule but an emergent phenomenon.<n>The novelty of QTI lies in its embedding of collapse within the conceptual language of critical phenomena in statistical physics.
  arXiv  Detail & Related papers  (2025-08-25T20:30:56Z)
• Disjointness of inertial KMS states and the role of Lorentz symmetry in thermalization [0.0]
  We show that a state satisfying the KMS condition relative to one reference frame is far from thermal equilibrium relative to other frames. We argue that a coupled system consisting of an Unruh-DeWitt detector cannot approach a KMS state at late times under generic conditions. This leads to an illustration of the physical differences between heat baths in inertial systems and the apparent "heat bath" of the Unruh effect from the viewpoint of moving detectors.
  arXiv  Detail & Related papers  (2024-02-22T18:54:04Z)
• Observation of partial and infinite-temperature thermalization induced by repeated measurements on a quantum hardware [62.997667081978825]
  We observe partial and infinite-temperature thermalization on a quantum superconducting processor. We show that the convergence does not tend to a completely mixed (infinite-temperature) state, but to a block-diagonal state in the observable basis.
  arXiv  Detail & Related papers  (2022-11-14T15:18:11Z)
• 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)
• Uniformly accelerated Brownian oscillator in (2+1)D: temperature-dependent dissipation and frequency shift [0.0]
  We consider an Unruh-DeWitt detector coupled to a quantum scalar field in the (2+1)-dimensional Minkowski spacetime. We find that both the accelerated detector's dissipation rate and the shift of its frequency caused by the coupling to the field bath depend on the acceleration temperature.
  arXiv  Detail & Related papers  (2022-01-20T16:45:38Z)
• General features of the thermalization of particle detectors and the Unruh effect [0.0]
  We study the thermalization of smeared particle detectors that couple locally to $any$ operator in a quantum field theory in curved spacetimes. We show that if the field state satisfies the KMS condition with inverse temperature $beta$ with respect to the detector's local notion of time evolution, reasonable assumptions ensure that the probe thermalizes to the temperature $1/beta$ in the limit of long interaction times.
  arXiv  Detail & Related papers  (2021-06-28T18:00:05Z)
• 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)
• Equivalence of approaches to relational quantum dynamics in relativistic settings [68.8204255655161]
  We show that the trinity' of relational quantum dynamics holds in relativistic settings per frequency superselection sector. We ascribe the time according to the clock subsystem to a POVM which is covariant with respect to its (quadratic) Hamiltonian.
  arXiv  Detail & Related papers  (2020-07-01T16:12:24Z)

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.