In a recent experiment [M. Feld et al., Nature (London) 480, 75 (2011); B. Frohlich et al., Phys. Rev. Lett. 109, 130403 (2012)], a pairing gap was detected in a two-dimensional (2D) Fermi gas with attractive interaction at temperatures where superfluidity does not occur. The question remains open as to whether this gap is a pseudogap phenomenon or is due to a molecular state. In this paper, by using a t-matrix approach, we reproduce quite well the experimental data for a 2D Fermi gas, and set the boundary between the pseudogap and molecular regimes. We also show that pseudogap phenomena occurring in 2D and 3D can be related through a variable spanning the BCS-BEC crossover in a universal way.
F. Marsiglio, PIERI, P., PERALI, A., PALESTINI, F., STRINATI CALVANESE, G. (2015). Pairing effects in the normal phase of a two-dimensional Fermi gas. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 91(5), 054509-1-054509-10 [10.1103/PhysRevB.91.054509].
Pairing effects in the normal phase of a two-dimensional Fermi gas
PIERI, Pierbiagio;
2015
Abstract
In a recent experiment [M. Feld et al., Nature (London) 480, 75 (2011); B. Frohlich et al., Phys. Rev. Lett. 109, 130403 (2012)], a pairing gap was detected in a two-dimensional (2D) Fermi gas with attractive interaction at temperatures where superfluidity does not occur. The question remains open as to whether this gap is a pseudogap phenomenon or is due to a molecular state. In this paper, by using a t-matrix approach, we reproduce quite well the experimental data for a 2D Fermi gas, and set the boundary between the pseudogap and molecular regimes. We also show that pseudogap phenomena occurring in 2D and 3D can be related through a variable spanning the BCS-BEC crossover in a universal way.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
