Bound states of two spin-(1/2) fermions in a synthetic non-Abelian gauge field

Journal Article · Tue Mar 01 00:00:00 EST 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.83.094515· OSTI ID:21538206

Vyasanakere, Jayantha P; Shenoy, Vijay B ^[1]

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1. Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560 012 (India)

We study the bound states of two spin-(1/2) fermions interacting via a contact attraction (characterized by a scattering length) in the singlet channel in three-dimensional space in presence of a uniform non-Abelian gauge field. The configuration of the gauge field that generates a Rashba-type spin-orbit interaction is described by three coupling parameters ({lambda}{sub x},{lambda}{sub y},{lambda}{sub z}). For a generic gauge field configuration, the critical scattering length required for the formation of a bound state is negative, i.e., shifts to the ''BCS side'' of the resonance. Interestingly, we find that there are special high-symmetry configurations (e.g., {lambda}{sub x}={lambda}{sub y}={lambda}{sub z}) for which there is a two-body bound state for anyscattering length however small and negative. Remarkably, the bound-state wave functions obtained for such configurations have nematic spin structure similar to those found in liquid {sup 3}He. Our results show that the BCS-BEC (Bose-Einstein condensation) crossover is drastically affected by the presence of a non-Abelian gauge field. We discuss possible experimental signatures of our findings both at high and low temperatures.

• OSTI ID: 21538206
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 83, Issue 9; Other Information: DOI: 10.1103/PhysRevB.83.094515; (c) 2011 American Institute of Physics; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOSE-EINSTEIN CONDENSATION
BOUND STATE
CONFIGURATION
FERMIONS
GAUGE INVARIANCE
HELIUM 3
LIQUIDS
L-S COUPLING
RESONANCE
SCATTERING LENGTHS
SPIN
SYMMETRY
THREE-DIMENSIONAL CALCULATIONS
TWO-BODY PROBLEM
WAVE FUNCTIONS
ANGULAR MOMENTUM
COUPLING
DIMENSIONS
EVEN-ODD NUCLEI
FLUIDS
FUNCTIONS
HELIUM ISOTOPES
INTERMEDIATE COUPLING
INVARIANCE PRINCIPLES
ISOTOPES
LENGTH
LIGHT NUCLEI
MANY-BODY PROBLEM
NUCLEI
PARTICLE PROPERTIES
STABLE ISOTOPES