Spectroscopic Signatures of Nonequilibrium Pairing in Atomic Fermi Gases
Abstract
We determine the radio-frequency (rf) spectra for nonstationary states of a fermionic condensate produced by a rapid switch of the scattering length. The rf spectrum of the nonequilibrium state with constant BCS order parameter has two features in contrast with equilibrium where there is a single peak. The additional feature reflects the presence of excited pairs in the steady state. In the state characterized by periodically oscillating order parameter, the rf-absorption spectrum contains two sequences of peaks spaced by the frequency of oscillations. Satellite peaks appear due to a process where a rf photon in addition to breaking a pair emits or absorbs oscillation quanta.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2007
- DOI:
- 10.1103/PhysRevLett.99.160402
- arXiv:
- arXiv:0705.2069
- Bibcode:
- 2007PhRvL..99p0402D
- Keywords:
-
- 05.30.Fk;
- 32.80.-t;
- 74.25.Gz;
- Fermion systems and electron gas;
- Photon interactions with atoms;
- Optical properties;
- Condensed Matter - Superconductivity;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 4 pages, 5 figures