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Title: Photoemission spectrum and effect of inhomogeneous pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas

Abstract

We investigate the photoemission-type spectrum in a cold Fermi gas which was recently measured by the JILA group [Stewart et al., Nature (London) 454, 744 (2008)]. 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.

Authors:
;  [1];  [1]
  1. Department of Physics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)
Publication Date:
OSTI Identifier:
21456964
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 82; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.82.033629; (c) 2010 The American Physical Society; Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 74 ATOMIC AND MOLECULAR PHYSICS; APPROXIMATIONS; ATOMS; BCS THEORY; BOSE-EINSTEIN CONDENSATION; COUPLING; DENSITY; EMISSION SPECTRA; ENERGY GAP; FERMI GAS; FLUCTUATIONS; PHOTOEMISSION; POTENTIALS; S MATRIX; TRAPS; CALCULATION METHODS; EMISSION; MATRICES; PHYSICAL PROPERTIES; SECONDARY EMISSION; SPECTRA; VARIATIONS

Citation Formats

Tsuchiya, Shunji, Ohashi, Yoji, CREST, and Watanabe, Ryota. Photoemission spectrum and effect of inhomogeneous pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas. United States: N. p., 2010. Web. doi:10.1103/PHYSREVA.82.033629.
Tsuchiya, Shunji, Ohashi, Yoji, CREST, & Watanabe, Ryota. Photoemission spectrum and effect of inhomogeneous pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas. United States. https://doi.org/10.1103/PHYSREVA.82.033629
Tsuchiya, Shunji, Ohashi, Yoji, CREST, and Watanabe, Ryota. Wed . "Photoemission spectrum and effect of inhomogeneous pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas". United States. https://doi.org/10.1103/PHYSREVA.82.033629.
@article{osti_21456964,
title = {Photoemission spectrum and effect of inhomogeneous pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas},
author = {Tsuchiya, Shunji and Ohashi, Yoji and CREST and Watanabe, Ryota},
abstractNote = {We investigate the photoemission-type spectrum in a cold Fermi gas which was recently measured by the JILA group [Stewart et al., Nature (London) 454, 744 (2008)]. 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.},
doi = {10.1103/PHYSREVA.82.033629},
url = {https://www.osti.gov/biblio/21456964}, journal = {Physical Review. A},
issn = {1050-2947},
number = 3,
volume = 82,
place = {United States},
year = {2010},
month = {9}
}