Correlated decoherence in a common environment activated by relative motion

TL;DR

This paper investigates how relative motion in a common environment causes correlated decoherence in boundary subsystems, revealing a threshold velocity for the onset of irreversible decoherence and linking motion-induced excitations to environmental noise.

Contribution

It introduces a Gaussian open-system framework to analyze motion-induced correlated decoherence, identifying a velocity threshold and the roles of coherent mediation and noise components.

Findings

Below threshold, environment acts mainly as a coherent mediator.

Above threshold, a resonant shell enables finite cross-noise and irreversible decoherence.

Motion-induced excitation production is directly connected to correlated decoherence signatures.

Abstract

We study two spatially separated boundary subsystems coupled to a common structured environment under relative motion in a Gaussian open-system framework. By integrating out the environment, we obtain an influence functional governed by a dressed environmental correlator evaluated at the boundary positions, which encodes both coherent mediation and correlated fluctuations. Relative motion opens a correlated decoherence channel through Doppler-shifted spectral overlap of the boundary excitations, leading to a kinematic threshold at $v>2u_\phi$. Below threshold, the dominant resonant contribution to the off-diagonal noise kernel is absent and the environment acts predominantly as a coherent mediator at leading resonant order. Above threshold, a resonant shell opens and the same environment supports a finite cross-noise channel, producing irreversible correlated decoherence. In the reduced dynamics, coherent coupling is governed by the retarded component of the dressed correlator, while the decoherence rate is controlled by its Hadamard component. These results establish a direct connection between motion-induced excitation production and correlated decoherence in open quantum systems, and point to experimentally accessible signatures in superconducting--phononic platforms through excess correlated dephasing.