Relativistic BCS-BEC crossover at zero temperature
- Physics Department, Tsinghua University, Beijing 100084 (China)
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.
- OSTI ID:
- 21020516
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 75, Issue 9; Other Information: DOI: 10.1103/PhysRevD.75.096003; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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