Observation of coherent quench dynamics in a metallic many-body state of fermionic atoms

TL;DR

This study demonstrates the first observation of coherent quench dynamics in a fermionic many-body state using ultracold atoms, revealing long-lived oscillations driven by Fermi-Bose interactions, which can probe correlations in fermionic quantum systems.

Contribution

It reports the first experimental observation of coherent quench dynamics in a metallic fermionic state, expanding nonequilibrium studies beyond bosonic systems.

Findings

Long-lived coherent oscillations in fermionic momentum distribution

Oscillation period determined by Fermi-Bose interaction energy

Coherent quench dynamics as a probe for fermionic correlations

Abstract

Quantum simulation with ultracold atoms has become a powerful technique to gain insight into interacting many-body systems. In particular, the possibility to study nonequilibrium dynamics offers a unique pathway to understand correlations and excitations in strongly interacting quantum matter. So far, coherent nonequilibrium dynamics has exclusively been observed in ultracold many-body systems of bosonic atoms. Here we report on the observation of coherent quench dynamics of fermionic atoms. A metallic state of ultracold spin-polarised fermions is prepared along with a Bose-Einstein condensate in a shallow three-dimensional optical lattice. After a quench that suppresses tunnelling between lattice sites for both the fermions and the bosons, we observe long-lived coherent oscillations in the fermionic momentum distribution, with a period that is determined solely by the Fermi-Bose interaction energy. Our results show that coherent quench dynamics can serve as a sensitive probe for correlations in delocalised fermionic quantum states and for quantum metrology.