Realization of an Excited, Strongly Correlated Quantum Gas Phase

TLDR

Ultracold atomic physics enables study of strongly correlated many‑body systems in low dimensions, yet only ground‑state phases have been accessible so far. The study aims to realize and control a highly excited, strongly correlated quantum phase in a one‑dimensional cesium gas across a confinement‑induced resonance. The authors employ a tunable cesium gas in one dimension, measuring stiffness and energy to track the repulsive‑to‑attractive interaction crossover. The experiment demonstrates a metastable excited many‑body phase with strong correlations, opening avenues for investigating its dynamical properties.

Abstract

Ultracold atomic physics offers myriad possibilities to study strongly correlated many-body systems in lower dimensions. Typically, only ground state phases are accessible. Using a tunable quantum gas of bosonic cesium atoms, we realize and control in one dimensional geometry a highly excited quantum phase that is stabilized in the presence of attractive interactions by maintaining and strengthening quantum correlations across a confinement-induced resonance. We diagnose the crossover from repulsive to attractive interactions in terms of the stiffness and the energy of the system. Our results open up the experimental study of metastable excited many-body phases with strong correlations and their dynamical properties.