Single-particle-excitation spectrum of degenerate Fermi gases in a ring cavity
Abstract
By considering spin-1/2 degenerate Fermi gases in a ring cavity where strong interaction between atoms and light gives rise to superradiance, we find that the cavity dissipation can cause a severe broadening in some special cases, breaking down the quasiparticle picture which has been constantly assumed in mean-field theory studies. This broadening happens when the band gap is resonant with polariton excitation energy. Interestingly enough, this broadening is highly spin selective, depending on how the fermions are filled, and the spectrum becomes asymmetric due to dissipation. Further, a nonmonotonous dependence of the maximal broadening of the spectrum on the cavity decay rate κ is found and the largest broadening emerges at κ , comparable to the recoil energy.
- Publication:
-
Physical Review A
- Pub Date:
- September 2017
- DOI:
- 10.1103/PhysRevA.96.033841
- arXiv:
- arXiv:1706.10204
- Bibcode:
- 2017PhRvA..96c3841F
- Keywords:
-
- Condensed Matter - Quantum Gases
- E-Print:
- 10 pages, 10 figures