Resonantly paired fermionic superfluids
Abstract
We present a theory of a degenerate atomic Fermi gas, interacting through a narrow Feshbach resonance, whose position and therefore strength can be tuned experimentally, as demonstrated recently in ultracold trapped atomic gases. The distinguishing feature of the theory is that its accuracy is controlled by a dimensionless parameter proportional to the ratio of the width of the resonance to Fermi energy. The theory is therefore quantitatively accurate for a narrow Feshbach resonance. In the case of a narrow swave resonance, our analysis leads to a quantitative description of the crossover between a weakly paired BCS superconductor of overlapping Cooper pairs and a strongly paired molecular BoseEinstein condensate of diatomic molecules. In the case of pairing via a pwave resonance, that we show is always narrow for a sufficiently low density, we predict a detuningtemperature phase diagram, that in the course of a BCSBEC crossover can exhibit a host of thermodynamically distinct phases separated by quantum and classical phase transitions. For an intermediate strength of the dipolar anisotropy, the system exhibits a p {sub x} + ip {sub y} paired superfluidity that undergoes a topological phase transition between a weakly coupled gapless ground state at large positive detuning and amore »
 Authors:
 Department of Physics, University of Colorado, Boulder, CO 80309 (United States). Email: victor.gurarie@colorado.edu
 Department of Physics, University of Colorado, Boulder, CO 80309 (United States)
 Publication Date:
 OSTI Identifier:
 20845987
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Annals of Physics (New York); Journal Volume: 322; Journal Issue: 1; Other Information: DOI: 10.1016/j.aop.2006.10.009; PII: S00034916(06)002399; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCURACY; ANISOTROPY; BOSEEINSTEIN CONDENSATION; COOPER PAIRS; EXCITATION; FERMI GAS; FERMIONS; GASES; GROUND STATES; P WAVES; PHASE DIAGRAMS; PHASE TRANSFORMATIONS; RESONANCE; S WAVES; SUPERCONDUCTORS; SUPERFLUIDITY; TOPOLOGY; VORTICES
Citation Formats
Gurarie, V., and Radzihovsky, L. Resonantly paired fermionic superfluids. United States: N. p., 2007.
Web. doi:10.1016/j.aop.2006.10.009.
Gurarie, V., & Radzihovsky, L. Resonantly paired fermionic superfluids. United States. doi:10.1016/j.aop.2006.10.009.
Gurarie, V., and Radzihovsky, L. Mon .
"Resonantly paired fermionic superfluids". United States.
doi:10.1016/j.aop.2006.10.009.
@article{osti_20845987,
title = {Resonantly paired fermionic superfluids},
author = {Gurarie, V. and Radzihovsky, L.},
abstractNote = {We present a theory of a degenerate atomic Fermi gas, interacting through a narrow Feshbach resonance, whose position and therefore strength can be tuned experimentally, as demonstrated recently in ultracold trapped atomic gases. The distinguishing feature of the theory is that its accuracy is controlled by a dimensionless parameter proportional to the ratio of the width of the resonance to Fermi energy. The theory is therefore quantitatively accurate for a narrow Feshbach resonance. In the case of a narrow swave resonance, our analysis leads to a quantitative description of the crossover between a weakly paired BCS superconductor of overlapping Cooper pairs and a strongly paired molecular BoseEinstein condensate of diatomic molecules. In the case of pairing via a pwave resonance, that we show is always narrow for a sufficiently low density, we predict a detuningtemperature phase diagram, that in the course of a BCSBEC crossover can exhibit a host of thermodynamically distinct phases separated by quantum and classical phase transitions. For an intermediate strength of the dipolar anisotropy, the system exhibits a p {sub x} + ip {sub y} paired superfluidity that undergoes a topological phase transition between a weakly coupled gapless ground state at large positive detuning and a strongly paired fully gapped molecular superfluid for a negative detuning. In two dimensions the former state is characterized by a Pfaffian ground state exhibiting topological order and nonAbelian vortex excitations familiar from fractional quantum Hall systems.},
doi = {10.1016/j.aop.2006.10.009},
journal = {Annals of Physics (New York)},
number = 1,
volume = 322,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}

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