BCS-BEC crossover at T=0: A dynamical mean-field theory approach

Thumbnail Image

Files

fac_RanderiaM_PhysicalReviewB_2005_72_2.pdf (155.63 KB)

Date

2005-07-13

Authors

Journal Title

Journal ISSN

Volume Title

Publisher

American Physical Society

Research Projects

Organizational Units

Journal Issue

Abstract

We study the T=0 crossover from the BCS superconductivity to Bose-Einstein condensation in the attractive Hubbard Model within dynamical mean field theory (DMFT) in order to examine the validity of Hartree-Fock-Bogoliubov (HFB) mean field theory, usually used to describe this crossover, and to explore the physics beyond it. Quantum fluctuations are incorporated using iterated perturbation theory as the DMFT impurity solver. We find that these fluctuations lead to large quantitative effects in the intermediate coupling regime, leading to a reduction of both the superconducting order parameter and the energy gap relative to the HFB results. A qualitative change is found in the single-electron spectral function, which now shows an incoherent spectral weight for energies larger than three times the gap, in addition to the usual Bogoliubov quasiparticle peaks.

Description

Keywords

Citation

Arti Garg, H. R. Krishnamurthy, Mohit Randeria, "BCS-BEC crossover at T=0: A dynamical mean-field theory approach," Physical Review B 72, no. 2 (2005), doi:10.1103/PhysRevB.72.024517

URI

http://hdl.handle.net/1811/48148

Collections

Ohio State University Research and Scholarship