Ultra-large Rydberg dimers in optical lattices

TL;DR

This paper explores the properties and dynamics of ultra-large Rydberg dimers in optical lattices, revealing their potential for simulating strongly correlated electronic systems with tunable interactions.

Contribution

It introduces the existence of molecular Rydberg states with large equilibrium distances and binding energies, and analyzes electron hopping and interactions in excited ultracold atom lattices.

Findings

Existence of Rydberg molecular states with large equilibrium distances.

Computed hopping rates and interaction matrix elements for highly excited electrons.

Potential for simulating strongly correlated electronic systems with tunable parameters.

Abstract

We investigate the dynamics of Rydberg electrons excited from the ground state of ultracold atoms trapped in an optical lattice. We first consider a lattice comprising an array of double-well potentials, where each double well is occupied by two ultracold atoms. We demonstrate the existence of molecular states with equilibrium distances of the order of experimentally attainable inter-well spacings and binding energies of the order of 10^3 GHz. We also consider the situation whereby ground-state atoms trapped in an optical lattice are collectively excited to Rydberg levels, such that the charge-density distributions of neighbouring atoms overlap. We compute the hopping rate and interaction matrix elements between highly-excited electrons separated by distances comparable to typical lattice spacings. Such systems have tunable interaction parameters and a temperature ~10^{-4} times smaller than the Fermi temperature, making them potentially attractive for the study and simulation of strongly correlated electronic systems.