Atom interferometric detection of the pairing order parameter in a Fermi gas

TL;DR

This paper proposes interferometric methods to detect pair condensation in a Fermi gas by analyzing atom counting statistics and matter-wave gratings, providing experimental tools for observing superfluid order.

Contribution

It introduces two novel interferometric schemes for directly detecting the pairing order parameter in a Fermi gas, linking long-range order to measurable interference patterns.

Findings

Interferometric schemes can reveal pairing order in Fermi gases.

Long-range order affects atom counting statistics.

Matter-wave gratings indicate pair condensation.

Abstract

We propose two interferometric schemes to experimentally detect the onset of pair condensation in a two spin-component Fermi gas. Two atomic wave-packets are coherently extracted from the gas at different positions and are mixed by a matter-wave beam splitter: we show that the spatial long range order of the atomic pairs in the gas then reflects in the atom counting statistics in the output channels of the beam splitter. Alternatively, the same long range order is also shown to create a matter-wave grating in the overlapping region of the two extracted wave-packets, grating that can be revealed by a light scattering experiment.