Creating collective many-body states with highly excited atoms

TL;DR

This paper explores how highly excited atoms in a ring lattice can form collective many-body states that resemble free fermions, with potential experimental access via laser parameter tuning.

Contribution

It introduces a regime where weak interactions lead to many-body states that can be described as free spinless fermions, providing new insights into collective excitations.

Findings

Many-body states can be expressed as free fermions

Correlation functions of these states are characterized

Experimental access via laser parameter variation is demonstrated

Abstract

We study the collective excitation of a gas of highly excited atoms confined to a large spacing ring lattice, where the ground and the excited states are coupled resonantly via a laser field. Our attention is focused on the regime where the interaction between the highly excited atoms is very weak in comparison to the Rabi frequency of the laser. We demonstrate that in this case the many-body excitations of the system can be expressed in terms of free spinless fermions. The complex many-particle states arising in this regime are characterized and their properties, e.g. their correlation functions, are studied. In addition we investigate how one can actually experimentally access some of these many-particle states by a temporal variation of the laser parameters.