Extended coherently delocalized states in a frozen Rydberg gas

TL;DR

This paper demonstrates that in a frozen Rydberg gas, many single-exciton states are surprisingly delocalized, with their properties tunable via microwave pulses and interaction parameters, revealing two distinct types of eigenstates.

Contribution

The study reveals the coexistence of localized and delocalized eigenstates in a Rydberg gas and shows how to control their contributions using microwave excitation and Rydberg blockade effects.

Findings

Many eigenstates are delocalized over roughly a quarter of the atoms.

Two types of eigenstates identified: localized from clusters and extended networks.

Delocalized states can be selectively excited and manipulated.

Abstract

The long-range dipole-dipole interaction can create delocalized states due to the exchange of excitation between Rydberg atoms. We show that even in a random gas many of the single-exciton eigenstates are surprisingly delocalized, composed of roughly one quarter of the participating atoms. We identify two different types of eigenstates: one which stems from strongly-interacting clusters, resulting in localized states, and one which extends over large delocalized networks of atoms. These two types of states can be excited and distinguished by appropriately tuned microwave pulses, and their relative contributions can be modified by the Rydberg blockade and the choice of microwave parameters.