Coherent population oscillation from a Fermi atom-molecule dark state

TL;DR

This paper demonstrates the existence of a stable macroscopic atom-molecule dark state in fermionic systems, enabling coherent oscillations between molecular BEC and atomic BCS states, with potential applications in quantum control.

Contribution

It introduces a novel fermionic dark state combining molecular BEC and atomic BCS pairing, and explores its coherent oscillations driven by external lasers.

Findings

Existence of a robust fermionic dark state

Observation of coherent oscillations between molecules and atom pairs

Interpretation of oscillation frequencies via collective excitations

Abstract

We show that a robust macroscopic atom-molecule dark state can exist in fermionic systems, which represents a coherent superposition between the ground molecular BEC and the atomic BCS paired state. We take advantage of the tunability offered by external laser fields, and explore this superposition for demonstrating coherent oscillations between ground molecules and atom pairs. We interpret the oscillation frequencies in terms of the collective excitations of the dark state.