Absence of fermionic quasiparticles in the superfluid state of the attractive fermi gas

作者：Lerch Nils^*; Bartosch Lorenz; Kopietz Peter

来源：Physical Review Letters, 2008, 100(5): 050403.

DOI：10.1103/PhysRevLett.100.050403

We calculate the effect of order parameter fluctuations on the fermionic single-particle excitations in the superfluid state of neutral fermions interacting with short-range attractive forces. We show that in dimensions D <= 3 the singular effective interaction between the fermions mediated by the gapless Bogoliubov-Anderson mode prohibits the existence of well-defined quasiparticles. We explicitly calculate the single-particle spectral function in the BEC regime in D=3 and show that in this case the quasiparticle residue and the density of states are logarithmically suppressed.

• 出版日期2008-2-8