PIRSA:10050081

Emergent gauge theories in Quantum spin Hall superconductor Josephson arrays and cold atom system

Xu, C. (2010). Emergent gauge theories in Quantum spin Hall superconductor Josephson arrays and cold atom system. Perimeter Institute. https://pirsa.org/10050081

Xu, Cenke. Emergent gauge theories in Quantum spin Hall superconductor Josephson arrays and cold atom system. Perimeter Institute, May. 28, 2010, https://pirsa.org/10050081 

          @misc{ pirsa_PIRSA:10050081,
            doi = {10.48660/10050081},
            url = {https://pirsa.org/10050081},
            author = {Xu, Cenke},
            keywords = {},
            language = {en},
            title = {Emergent gauge theories in Quantum spin Hall superconductor Josephson arrays and cold atom system},
            publisher = {Perimeter Institute},
            year = {2010},
            month = {may},
            note = {PIRSA:10050081 see, \url{https://pirsa.org}}
          }

Cenke Xu

University of California, Santa Barbara

Talk number
PIRSA:10050081
Collection
Talk Type
Abstract
We study a superconductor-ferromagnet-superconductor (SC-FM-SC) Josephson junction array deposited on top of a two-dimensional quantum spin Hall (QSH) insulator. The existence of Majorana bound states at the interface between SC and FM gives rise to charge-e tunneling, in addition to the usual charge-2e Cooper pair tunneling, between neighboring superconductor islands. Moreover, because Majorana fermions encode the information of charge number parity, an exact Z_2 gauge structure naturally emerges and leads to many new insulating phases, including a deconfined phase where electrons fractionalize into charge-e bosons and topological defects. We will also discuss the ultracold alkaline earth atoms trapped in optical lattice, which naturally has a SU(N) spin symmetry with N as large as 10. An SU(2)xU(1) gauge theory emerges in a large part of the phase diagram of this system.