Microscopic Realization of Two-Dimensional Bosonic Topological Insulators
It is well known that a bosonic Mott insulator can be realized by condensing vortices of a boson condensate. Usually, a vortex becomes an antivortex (and vice versa) under time reversal symmetry, and the condensation of vortices results in a trivial Mott insulator. However, if each vortex or antivor...
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society,
2015-01-13T14:45:09Z.
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| Subjects: | |
| Online Access: | Get fulltext |
| Summary: | It is well known that a bosonic Mott insulator can be realized by condensing vortices of a boson condensate. Usually, a vortex becomes an antivortex (and vice versa) under time reversal symmetry, and the condensation of vortices results in a trivial Mott insulator. However, if each vortex or antivortex interacts with a spin trapped at its core, the time reversal transformation of the composite vortex operator will contain an extra minus sign. It turns out that such a composite vortex condensed state is a bosonic topological insulator (BTI) with gapless boundary excitations protected by U(1) ⋊ Z[T over 2] symmetry. We point out that in BTI, an external π-flux monodromy defect carries a Kramers doublet. We propose lattice model Hamiltonians to realize the BTI phase, which might be implemented in cold atom systems or spin-1 solid state systems. Perimeter Institute for Theoretical Physics National Science Foundation (U.S.) (Grant DMR-1005541) National Natural Science Foundation (China) (11274192) Templeton Foundation (Grant 39901) |
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