Subradiance in multiply excited states of dipole-coupled V-type atoms

Institut für Theoretische Physik, Universität Innsbruck - Technikerstr. 21a, A-6020 Innsbruck, Austria

Received: 5 July 2019
Accepted: 26 November 2019

Abstract

We generalize the theoretical modeling of collective atomic super- and subradiance to the multilevel case including spontaneous emission from several excited states towards a common ground state. We show that in a closely packed ensemble of N atoms with N –1 distinct excited states each, one can find a new class of non-radiating dark states, which allows for long-term storage of N –1 photonic excitations. Via dipole-dipole coupling only a single atom in the ground state is sufficient in order to suppress the decay of all N –1 other atoms. By means of some generic geometric configurations, like a triangle of V-type atoms or a chain of atoms with a transition, we study such subradiance including dipole-dipole interactions and show that even at finite distances long lifetimes can be observed. While generally hard to prepare deterministically, we identify various possibilities for a probabilistic preparation via a phase-controlled laser pump and decay.