Intermittent decoherence blockade in a chiral ring environment

TL;DR

This paper demonstrates that in a chiral ring environment, decoherence can be intermittently suppressed through quantum interference effects, without relying on dark states, resulting in a staircase decay pattern.

Contribution

It introduces the concept of intermittent decoherence blockade caused by delayed quantum feedback in a chiral ring environment, challenging the traditional dark state paradigm.

Findings

Decoherence suppression occurs intermittently without dark states.

The decay process exhibits a non-exponential staircase pattern.

Interference between present and past emitted light causes the effect.

Abstract

It has long been recognized that emission of radiation from atoms is not an intrinsic property of individual atoms themselves, but it is largely affected by the characteristics of the photonic environment and by the collective interaction among the atoms. A general belief is that preventing full decay and/or decoherence requires the existence of dark states, i.e., dressed light-atom states that do not decay despite the dissipative environment. Here, we show that, contrary to such a common wisdom, decoherence suppression can be intermittently achieved on a limited time scale, without the need for any dark state, when the atom is coupled to a chiral ring environment, leading to a highly non-exponential staircase decay. This effect, that we refer to as intermittent decoherence blockade, arises from periodic destructive interference between light emitted in the present and light emitted in the past, i.e., from delayed coherent quantum feedback.