Symmetry Protected Topological Order and Spin Susceptibility in Superfluid 3He-B
Symmetry Protected Topological Order and Spin Susceptibility in Superfluid 3He-B
复制标题
DOI：
10.1103/physrevlett.109.165301
复制
发表时间：
2012-10-16
影响因子：
8.6
通讯作者：
Machida, Kazushige
中科院分区：
文献类型：
--
作者：
Mizushima, Takeshi;Sato, Masatoshi;Machida, Kazushige
我们证明了在特定方向磁场作用下的超流He-3-B由于离散的对称性而保持拓扑，即在对称保护的拓扑序中。由于对称保护的拓扑秩序，B相中螺旋面的Majorana费米子保持无隙，其伊辛自旋特性持续存在。我们揭示了塞曼磁场和偶极相互作用之间的竞争涉及一个反常的量子相变，在这个相变中，拓扑相变与自发的对称性破缺一起发生。基于准经典理论，我们阐明了相变伴随着表面自旋极化率的各向异性量子临界性，这在核磁共振实验中是可以检测到的。
We here demonstrate that the superfluid He-3-B under a magnetic field in a particular direction stays topological due to a discrete symmetry, that is, in a symmetry protected topological order. Because of the symmetry protected topological order, helical surface Majorana fermions in the B phase remain gapless and their Ising spin character persists. We unveil that the competition between the Zeeman magnetic field and dipole interaction involves an anomalous quantum phase transition in which a topological phase transition takes place together with spontaneous symmetry breaking. Based on the quasiclassical theory, we illustrate that the phase transition is accompanied by anisotropic quantum criticality of spin susceptibilities on the surface, which is detectable in NMR experiments.