Zeno Regime of Collective Emission: Non-Markovianity beyond Retardation

TL;DR

This paper investigates the non-Markovian dynamics of collective emission in a 1D waveguide, revealing that environmental memory effects significantly influence collective behavior beyond retardation effects, with implications for quantum information processing.

Contribution

It demonstrates that environmental memory effects play a dominant role in collective emission dynamics, extending understanding beyond traditional retardation-based explanations.

Findings

Memory effects are more pronounced in collective emission than in single-atom decay.

The Zeno regime causes a crossover from quadratic to exponential decay, affecting collective behavior.

Field memory effects impact the development of collective emission in waveguide setups.

Abstract

To build up a collective emission, the atoms in an ensemble must coordinate their behavior by exchanging virtual photons. We study this non-Markovian process in a subwavelength atom chain coupled to a one-dimensional (1D) waveguide and find that retardation is not the only cause of non-Markovianity. The other factor is the memory of the photonic environment, for which a single excited atom needs a finite time, the Zeno regime, to transition from quadratic decay to exponential decay. In the waveguide setup, this crossover has a time scale longer than the retardation, thus impacting the development of collective behavior. By comparing a full quantum treatment with an approach incorporating only the retardation effect, we find that the field memory effect, characterized by the population of atomic excitation, is much more pronounced in collective emissions than that in the decay of a single atom. Our results maybe useful for the dissipation engineering of quantum information processings based on compact atom arrays.