Modifying cooperative decay via disorder in atom arrays

TL;DR

This paper investigates how spatial disorder affects subradiant states in atomic arrays, finding that disorder generally does not enhance decay suppression and can sometimes accelerate decay, with implications for designing long-lived quantum states.

Contribution

The study extends understanding of disorder effects on subradiance in atomic arrays across different geometries, highlighting conditions where disorder is beneficial or detrimental.

Findings

Disorder has minimal average benefit for darker subradiant states in free space.

In dense systems, disorder can create close-packed subradiant states similar to Dicke states.

Disorder often accelerates decay rather than suppresses it.

Abstract

Atomic arrays can exhibit collective light emission when the transition wavelength exceeds their lattice spacing. Subradiant states take advantage of this phenomenon to drastically reduce their overall decay rate, allowing for long-lived states in dissipative open systems. We build on previous work to investigate whether or not disorder can further decrease the decay rate of a singly-excited atomic array. More specifically, we consider spatial disorder of varying strengths in a 1D half waveguide and in 1D, 2D, and 3D atomic arrays in free space and analyze the effect on the most subradiant modes. While we confirm that the dilute half waveguide exhibits an analog of Anderson localization, the dense half waveguide and free space systems can be understood through the creation of close-packed, few-body subradiant states similar to those found in the Dicke limit. In general, we find that disorder provides little advantage in generating darker subradiant states in free space on average and will often accelerate decay. However, one could potentially change interatomic spacing within the array to engineer specific subradiant states.