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Title: Relativistic BCS-BEC crossover at zero temperature

Abstract

We investigate the BCS-BEC (Bardeen-Cooper-Shriffer--Bose-Einstein condensation) crossover at zero temperature in the frame of a relativistic model. The universality of the BCS-BEC crossover for nonrelativistic systems breaks down in the relativistic case and the crossover can be induced by changing the density. When the effective scattering length is much less than the fermion Compton wavelength, we recover the nonrelativistic result if the gas is initially in a nonrelativistic state. At ultrastrong coupling where the scattering length is of the order of the Compton wavelength, a new BEC state appears. In this state the condensed bosons become nearly massless and antifermions are excited. The behavior of the Goldstone mode and the mixing between the amplitude and phase modes are significantly different in different condensed regions.

Authors:
;  [1]
  1. Physics Department, Tsinghua University, Beijing 100084 (China)
Publication Date:
OSTI Identifier:
21020516
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.75.096003; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; BCS THEORY; BOSE-EINSTEIN CONDENSATION; BOSONS; COMPTON WAVELENGTH; COUPLING; FERMIONS; QUANTUM FIELD THEORY; RELATIVISTIC RANGE; SCATTERING LENGTHS; TEMPERATURE ZERO K

Citation Formats

He Lianyi, and Zhuang Pengfei. Relativistic BCS-BEC crossover at zero temperature. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.096003.
He Lianyi, & Zhuang Pengfei. Relativistic BCS-BEC crossover at zero temperature. United States. doi:10.1103/PHYSREVD.75.096003.
He Lianyi, and Zhuang Pengfei. Tue . "Relativistic BCS-BEC crossover at zero temperature". United States. doi:10.1103/PHYSREVD.75.096003.
@article{osti_21020516,
title = {Relativistic BCS-BEC crossover at zero temperature},
author = {He Lianyi and Zhuang Pengfei},
abstractNote = {We investigate the BCS-BEC (Bardeen-Cooper-Shriffer--Bose-Einstein condensation) crossover at zero temperature in the frame of a relativistic model. The universality of the BCS-BEC crossover for nonrelativistic systems breaks down in the relativistic case and the crossover can be induced by changing the density. When the effective scattering length is much less than the fermion Compton wavelength, we recover the nonrelativistic result if the gas is initially in a nonrelativistic state. At ultrastrong coupling where the scattering length is of the order of the Compton wavelength, a new BEC state appears. In this state the condensed bosons become nearly massless and antifermions are excited. The behavior of the Goldstone mode and the mixing between the amplitude and phase modes are significantly different in different condensed regions.},
doi = {10.1103/PHYSREVD.75.096003},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 75,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}