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Title: Cooper pairing in non-Fermi liquids

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1180998
Grant/Contract Number:
DESC-8739- ER46872
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 91; Journal Issue: 11; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Metlitski, Max A., Mross, David F., Sachdev, Subir, and Senthil, T. Cooper pairing in non-Fermi liquids. United States: N. p., 2015. Web. doi:10.1103/PhysRevB.91.115111.
Metlitski, Max A., Mross, David F., Sachdev, Subir, & Senthil, T. Cooper pairing in non-Fermi liquids. United States. doi:10.1103/PhysRevB.91.115111.
Metlitski, Max A., Mross, David F., Sachdev, Subir, and Senthil, T. Wed . "Cooper pairing in non-Fermi liquids". United States. doi:10.1103/PhysRevB.91.115111.
@article{osti_1180998,
title = {Cooper pairing in non-Fermi liquids},
author = {Metlitski, Max A. and Mross, David F. and Sachdev, Subir and Senthil, T.},
abstractNote = {},
doi = {10.1103/PhysRevB.91.115111},
journal = {Physical Review B},
number = 11,
volume = 91,
place = {United States},
year = {Wed Mar 04 00:00:00 EST 2015},
month = {Wed Mar 04 00:00:00 EST 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevB.91.115111

Citation Metrics:
Cited by: 66works
Citation information provided by
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  • We study a two-dimensional continuum model of a dilute gas of fermions at {ital T}=0 interacting via a given two-body potential, with an aim to investigate superconductors with coherence length of the order of the interparticle spacing ({ital k}{sub {ital F}}{xi}{sub 0}{similar to}O(1)), a striking feature of the high-{ital T}{sub {ital c}} materials. We find that a two-body bound state in vacuum is a necessary and sufficient condition for an {ital s}-wave pairing instability. We also find that the existence of such a bound state in a higher-angular-momentum ({ital l}{gt}0) channel is not a necessary condition for an {ital l}-wavemore » pairing instability. We further investigate using a variational {ital ansatz} the evolution from a state with large overlapping Cooper pairs ({ital k}{sub {ital F}}{xi}{sub 0}{much gt}1) to one with Bose condensation of composite bosons ({ital k}{sub {ital F}}{xi}{sub 0}{much lt}1). For the {ital s}-wave case an exact solution of the variational equations shows a smooth crossover from one regime to the other at {ital T}=0. The {ital p}-wave solution has a weak singularity when the chemical potential goes through zero, which is the bottom of the band. We show, quite generally, independent of the dimensionality and of model details, that the gap--to--single-particle excitations is nodeless, even if the anisotropic pair wave function has nodes, when the coupling is strong enough that the chemical potential is negative.« less
  • We theoretically investigate Raman photoassociation of a degenerate Bose-Fermi mixture of atoms and the subsequent prospect for anomalous (Cooper) pairing between atoms and molecules. Stable fermionic molecules are created via free-bound-bound stimulated Raman adiabatic passage which, in contrast to purely bosonic systems, can occur in spite of collisions. With the leftover atomic condensate to enhance intrafermion interactions, the superfluid transition to atom-molecule Cooper pairs occurs at a temperature that is roughly an order of magnitude below what is currently feasible.
  • Similar to what has recently been achieved with Bose-Bose mixtures [G. Lamporesi, J. Catani, G. Barontini, Y. Nishida, M. Inguscio, and F. Minardi, Phys. Rev. Lett. 104, 153202 (2010)], mixed-dimensional Fermi-Fermi mixtures can be created by applying a species-selective one-dimensional optical lattice to a two-species Fermi gas ({sigma}{identical_to}({up_arrow},{down_arrow})), in such a way that both species are confined to quasi-two-dimensional geometries determined by their hoppings along the lattice direction. We investigated the ground-state phase diagram of superfluidity for such mixtures in the BCS-BEC evolution, and found normal, gapped superfluid, gapless superfluid, and phase separated regions. In particular, we found a stablemore » gapless superfluid phase where the unpaired {up_arrow} and {down_arrow} fermions coexist with the paired (or superfluid) ones in different momentum space regions. This phase is in some ways similar to the Sarma state found in mixtures with densities, but in our case, the gapless superfluid phase is unpolarized and most importantly it is stable against phase separation.« less
  • The influence of multiparticle correlation effects and Cooper pairing in an ultracold Fermi gas with a negative scattering length on the formation rate of molecules is investigated. Cooper pairing is shown to cause the formation rate of molecules to increase, as distinct from the influence of Bose-Einstein condensation in a Bose gas on this rate. This trend is retained in the entire range of temperatures below the critical one.