Anomalous dimers in quantum mixtures near broad resonances: Pauli blocking, Fermi surface dynamics, and implications

Journal Article · Fri Jul 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.013601· OSTI ID:22051342

Junliang, Song; Fei, Zhou ^[1]

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1. Institute for Quantum Optics and Quantum Information of the Austria Academy of Sciences, A-6020 Innsbruck (Austria)

We study the energetics and dispersion of anomalous dimers that are induced by the Pauli blocking effect in a quantum Fermi gas of majority atoms near interspecies resonances. Unlike in vacuum, we find that both the sign and magnitude of the dimer masses are tunable via Feshbach resonances. We also investigate the effects of particle-hole fluctuations on the dispersion of dimers and demonstrate that the particle-hole fluctuations near a Fermi surface (with Fermi momentum ({Dirac_h}/2{pi})k{sub F}) generally reduce the effective two-body interactions and the binding energy of dimers. Furthermore, in the limit of light minority atoms the particle-hole fluctuations disfavor the formation of dimers with a total momentum ({Dirac_h}/2{pi})k{sub F}, because near ({Dirac_h}/2{pi})k{sub F} the modes where the dominating particle-hole fluctuations appear are the softest. Our calculation suggests that near broad interspecies resonances when the minority-majority mass ratio m{sub B}/m{sub F} is smaller than a critical value (estimated to be 0.136), dimers in a finite-momentum channel are energetically favored over dimers in the zero-momentum channel. We apply our theory to quantum gases of {sup 6}Li{sup 40}K, {sup 6}Li{sup 87}Rb, {sup 40}K{sup 87}Rb, and {sup 6}Li{sup 23}Na near broad interspecies resonances, and discuss the limitations of our calculations and implications.

• OSTI ID: 22051342
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 84; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BINDING ENERGY
DIMERS
FERMI GAS
FERMI LEVEL
FLUCTUATIONS
HOLES
PARTICLES
PAULI PRINCIPLE
RESONANCE
TWO-BODY PROBLEM
VISIBLE RADIATION