Exotic Paired States with Anisotropic Spin-Dependent Fermi Surfaces

Journal Article · Fri Jul 10 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.025303· OSTI ID:21347045

Feiguin, Adrian E ^[1]; Fisher, Matthew P. A. ^[1]

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1. Microsoft Project Q, University of California, Santa Barbara, California 93106 (United States)

We propose a model for realizing exotic paired states in cold Fermi gases by using a spin-dependent optical lattice to engineer mismatched Fermi surfaces for each hyperfine species. The BCS phase diagram shows a stable paired superfluid state with coexisting pockets of momentum space with gapless unpaired carriers, similar to the Sarma state in polarized mixtures, but in our case the system is unpolarized. We propose the possible existence of an exotic 'Cooper-pair Bose-metal' phase, which has a gap for single fermion excitations but gapless and uncondensed 'Cooper-pair' excitations residing on a 'Bose surface' in momentum space.

• OSTI ID: 21347045
• Journal Information: Physical Review Letters, Vol. 103, Issue 2; Other Information: DOI: 10.1103/PhysRevLett.103.025303; (c) 2009 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
COOPER PAIRS
EXCITATION
FERMI GAS
FERMI LEVEL
FERMIONS
PHASE DIAGRAMS
SPIN
SUPERFLUIDITY
ANGULAR MOMENTUM
DIAGRAMS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
INFORMATION
PARTICLE PROPERTIES