1204.4780 (Takeshi Mizushima et al.)

Symmetry Protected Topological Order and Spin Susceptibility in
Superfluid 3He-B    [PDF]

Takeshi Mizushima, Masatoshi Sato, Kazushige Machida

We clarify the interplay of a Zeeman magnetic field and dipole interaction on surface helical Majorana fermions of superfluid 3He-B. We first reveal that the B-phase under a magnetic field in a particular direction stays topological due to a discrete symmetry, that is, in a symmetry protected topological phase. It is shown that the Ising spin character of the helical Majorana fermion is a direct consequence of the symmetry protected topological phase. Based on the quasiclassical theory, we demonstrate that the competition between the dipole interaction and the magnetic field involves the topological phase transition and simultaneously the spontaneous symmetry breaking of the discrete symmetry, which is accompanied by novel behaviors of spin susceptibilities on the surface.

View original: http://arxiv.org/abs/1204.4780