Topological phase, supercritical point, and emergent phenomena in an extended parafermion chain

Article

关键词: NEXT-NEAREST-NEIGHBOR;    ANTIFERROMAGNETIC XXZ CHAIN;    ENTANGLEMENT ENTROPY;    SPIN CHAIN;    SUPERCONDUCTOR;    MODEL;   

DOI  :  10.1103/PhysRevB.100.125101

来源: SCIE

【 摘 要 】

Topological orders and associated topological protected excitations with non-Abelian statistics have been widely explored in various platforms. The Z(3) parafermions are regarded as the most natural generation of the Majorana fermions to realize these topological orders. Here we investigate the topological phase and emergent Z(2) spin phases in an extended parafermion chain. This model exhibits a rich variety of phases, including not only topological ferromagnetic phase, which supports non-Abelian anyon excitation, but also spin-fluid, dimer, and chiral phases from the emergent Z(2) spin model. These phases correspond to various metallic and insulator phases with different orders realized by parafermions. We generalize the measurement tools in Z(2) spin models to fully characterize these phases and map out the corresponding phase diagram. Surprisingly, all the phase boundaries finally merge to a single supercritical (SC) point with infinite degeneracy. The phases surrounding this SC point can be regarded as phases under different types of symmetry breakings. This criteria may suggest a general principle to search these SC points in the other models. Our phase diagram also reveals the asymptotic behavior of the parafermion towards canonical fermions. Regarding the rather generality of emergent phenomena in parafermion models, this approach opens a wide range of intriguing applications in investigating the various exotic phases using parafermion models.

【 授权许可】

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