title: p-Wave superfluidity by spin-nematic Fermi surface deformation.
abstract: We study attractively interacting fermions on a square lattice with dispersion relations exhibiting strong spin-dependent anisotropy. The resulting Fermi surface mismatch suppresses the s-wave BCS-type instability, clearing the way for unconventional types of order. Unbiased sampling of the Feynman diagrammatic series using diagrammatic Monte Carlo methods reveals a rich phase diagram in the regime of intermediate coupling strength. Instead of a proposed Cooper-pair Bose metal phase [A. E. Feiguin and M. P. A. Fisher, Phys. Rev. Lett. 103, 025303 (2009)], we find an incommensurate density wave at strong anisotropy and two different p-wave superfluid states with unconventional symmetry at intermediate anisotropy.
authors.affiliation: Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Gukelberger
authors.affiliation: Physics Department, King's College, London WC2 R 2LS, United Kingdom.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Kozik
authors.affiliation: Department of Physics, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, University of Munich, Theresienstrasse 37, 80333 Munich, Germany.
authors.forename: Lode
authors.initials: L
authors.lastname: Pollet
authors.affiliation: Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-4525, USA.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Prokof'ev
authors.affiliation: Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Manfred
authors.initials: M
authors.lastname: Sigrist
authors.affiliation: Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-4525, USA.
authors.forename: Boris
authors.initials: B
authors.lastname: Svistunov
authors.affiliation: Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Troyer