Topological Septet Pairing with Spin-3/2 Fermions: High-Partial-Wave Channel Counterpart of the ^{3}He-B Phase

Phys Rev Lett. 2016 Aug 12;117(7):075301. doi: 10.1103/PhysRevLett.117.075301. Epub 2016 Aug 10.

Abstract

We systematically generalize the exotic ^{3}He-B phase, which not only exhibits unconventional symmetry but is also isotropic and topologically nontrivial, to arbitrary partial-wave channels with multicomponent fermions. The concrete example with four-component fermions is illustrated including the isotropic f-, p-, and d-wave pairings in the spin septet, triplet, and quintet channels, respectively. The odd partial-wave channel pairings are topologically nontrivial, while pairings in even partial-wave channels are topologically trivial. The topological index reaches the largest value of N^{2} in the p-wave channel (N is half of the fermion component number). The surface spectra exhibit multiple linear and even high order Dirac cones. Applications to multiorbital condensed matter systems and multicomponent ultracold large spin fermion systems are discussed.