Probing Fermionic Condensates by Fast-Sweep Projection onto Feshbach Molecules

TL;DR

This paper provides a detailed theoretical analysis of how fast magnetic field sweeps convert fermionic condensates into Feshbach molecules, clarifying the relationship between initial condensate fractions and measured molecular condensates.

Contribution

It calculates the exact dynamics of atom pairs during fast magnetic field sweeps, offering new insights into the conversion process in fermionic condensates.

Findings

Quantifies the number of molecules formed after fast sweeps in $^{40}$K and $^{6}$Li.

Establishes the relation between initial fermionic and molecular condensate fractions.

Analyzes effects of different sweep rates and magnetic field ranges.

Abstract

Fast sweep projection onto Feshbach molecules has been widely used as a probe of fermionic condensates. By determining the exact dynamics of a pair of atoms in time varying magnetic fields, we calculate the number of condensed and noncondensed molecules created after fast magnetic field sweeps from the BCS to the BEC side of the resonances in $^{40}$K and $^{6}$Li, for different sweep rates and a range of initial and final fields. We discuss the relation between the initial fermionic condensate fraction and the molecular condensate fraction measured after the sweep.