TY - JOUR
T1 - Low-dimensional pairing fluctuations and pseudogapped photoemission spectrum in a trapped two-dimensional Fermi gas
AU - Watanabe, Ryota
AU - Tsuchiya, Shunji
AU - Ohashi, Yoji
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/7/29
Y1 - 2013/7/29
N2 - We investigate strong-coupling properties of a trapped two-dimensional normal Fermi gas. Within the framework of a combined T-matrix theory with the local density approximation, we calculate the local density of states, as well as the photoemission spectrum, to see how two-dimensional pairing fluctuations affect these single-particle quantities. In the BCS (Bardeen-Cooper-Schrieffer)- BEC (Bose-Einstein condensation) crossover region, we show that the local density of states exhibits a dip structure in the trap center, which is more remarkable than the three-dimensional case. This pseudogap phenomenon is found to naturally lead to a double-peak structure in the photoemission spectrum. The peak-to-peak energy of the spectrum at p=0 agrees well with a recent experiment on a two-dimensional 40K Fermi gas. Since pairing fluctuations are sensitive to the dimensionality of a system, our results would be useful for the study of many-body physics in the BCS-BEC crossover regime of a two-dimensional Fermi gas.
AB - We investigate strong-coupling properties of a trapped two-dimensional normal Fermi gas. Within the framework of a combined T-matrix theory with the local density approximation, we calculate the local density of states, as well as the photoemission spectrum, to see how two-dimensional pairing fluctuations affect these single-particle quantities. In the BCS (Bardeen-Cooper-Schrieffer)- BEC (Bose-Einstein condensation) crossover region, we show that the local density of states exhibits a dip structure in the trap center, which is more remarkable than the three-dimensional case. This pseudogap phenomenon is found to naturally lead to a double-peak structure in the photoemission spectrum. The peak-to-peak energy of the spectrum at p=0 agrees well with a recent experiment on a two-dimensional 40K Fermi gas. Since pairing fluctuations are sensitive to the dimensionality of a system, our results would be useful for the study of many-body physics in the BCS-BEC crossover regime of a two-dimensional Fermi gas.
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U2 - 10.1103/PhysRevA.88.013637
DO - 10.1103/PhysRevA.88.013637
M3 - Article
AN - SCOPUS:84881490603
VL - 88
JO - Physical Review A
JF - Physical Review A
SN - 2469-9926
IS - 1
M1 - 013637
ER -