Decoherence of Schr\"odinger cat states in light of wave/particle duality

TL;DR

This paper challenges the standard decoherence model of Schr"odinger cat states, proposing a self-consistent approach that reveals significant disparities in wave-particle duality manifestations and quantum interference effects in open quantum systems.

Contribution

It introduces a novel framework for analyzing decoherence that accounts for pure state collections correlated with environmental records, contrasting with traditional Lindblad-based models.

Findings

Intensity-field correlations can deviate from monotonic decay.

Wigner functions show contrasting quantum interference based on photon counting.

Conditional detection events influence the electromagnetic field and charge diffusion.

Abstract

We challenge the standard picture of decohering Schr\"odinger cat states as an ensemble average obeying a Lindblad master equation, brought about locally from an irreversible interaction with an environment. We generate self-consistent collections of pure system states correlated with specific environmental records, corresponding to the function of the wave-particle correlator first introduced in Carmichael et al. [Phys. Rev. Lett. 85, 1855 (2000)]. In the spirit of Carmichael et al. [Coherent States: Past, Present and Future, pp. 75-91, World Scientific (1994)], we find that the complementary unravelings evince a pronounced disparity when the ``position'' and ``momentum'' of the damped cavity mode - an explicitly open quantum system - are measured. Intensity-field correlations may largely deviate from a monotonic decay, while Wigner functions of the cavity state display contrasting manifestations of quantum interference when conditioned on photon counts sampling a continuous photocurrent. In turn, the conditional photodetection events mark the contextual diffusion of both the net charge generated at the homodyne detector, and the electromagnetic field amplitude in the resonator.