Slow-light probe of Fermi pairing through an atom-molecule dark state

TL;DR

This paper proposes a method using slow light in a dark state setup to non-destructively diagnose Fermi pairing and atomic states in a quantum degenerate gas, leveraging EIT-like phenomena.

Contribution

It introduces a novel approach to probe Fermi pairing and atomic states via slow light propagation in a molecular dark state setup, connecting quantum optics with many-body physics.

Findings

Group velocity depends on atom type and pairing gap.

Measurement of group velocity reveals atomic pairing state.

Method provides a non-destructive diagnostic tool.

Abstract

We consider the two-color photooassociation of a quantum degenerate atomic gas into ground-state diatomic molecules via a molecular dark state. This process can be described in terms of a lambda level scheme that is formally analogous to the situation in electromagnetically-induced transparency (EIT) in atomic systems, and therefore can result in slow light propagation. We show that the group velocity of the light field depends explicitly on whether the atoms are bosons or fermions, as well as on the existence or absence of a pairing gap in the case of fermions, so that the measurement of the group velocity realizes a non-destructive diagnosis of the atomic state and the pairing gap.