Topological Polaritons in a Quantum Spin Hall Cavity

Alexander Janot; Bernd Rosenow; Gil Refael

doi:10.1103/physrevb.93.161111

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arXiv · 1501.04092

Topological Polaritons in a Quantum Spin Hall Cavity

Alexander Janot·Bernd Rosenow·Gil Refael

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Abstract

We study the topological structure of matter-light excitations, so called polaritons, in a quantum spin Hall insulator coupled to photonic cavity modes. We identify a topological invariant in the presence of time reversal (TR) symmetry, and demonstrate the existence of a TR-invariant topological phase. We find protected helical edge states with energies below the lower polariton branch and characteristic uncoupled excitonic states, both detectable by optical techniques. Applying a Zeeman field allows us to relate the topological index to the double coverage of the Bloch sphere by the polaritonic pseudospin.

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Alexander Janot, Bernd Rosenow, Gil Refael. 2015-01-16. Topological Polaritons in a Quantum Spin Hall Cavity. https://doi.org/10.1103/physrevb.93.161111

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