We investigate the photoemission-type spectrum in a cold Fermi gas which was recently measured by the JILA group. This quantity gives us very useful information about single-particle properties in the BCS-BEC crossover. In this paper, including pairing fluctuations within a T-matrix theory, as well as effects of a harmonic trap within the local density approximation, we show that spatially inhomogeneous pairing fluctuations due to the trap potential are an important key to understanding the observed spectrum. In the crossover region, while strong pairing fluctuations lead to the so-called pseudogap phenomenon in the trap center, such strong-coupling effects are found to be weak around the edge of the gas. Our results including this effect are shown to agree well with the recent photoemission data of the JILA group.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2010 Sep 30|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics