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arXiv · 2405.17431

Crystalline invariants of fractional Chern insulators

Ryohei Kobayashi·Yuxuan Zhang·Naren Manjunath·Maissam Barkeshli
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Abstract

In the presence of crystalline symmetry, topologically ordered states can acquire a host of symmetry-protected invariants. These determine the patterns of crystalline symmetry fractionalization of the anyons in addition to fractionally quantized responses to lattice defects. Here we show how ground state expectation values of partial rotations centered at high symmetry points can be used to extract crystalline invariants. Using methods from conformal field theory and G-crossed braided tensor categories, we develop a theory of invariants obtained from partial rotations, which apply to both Abelian and non-Abelian topological orders. We then perform numerical Monte Carlo calculations for projected parton wave functions of fractional Chern insulators, demonstrating remarkable agreement between theory and numerics. For the topological orders we consider, we show that the Hall conductivity, filling fraction, and partial rotation invariants fully characterize the crystalline invariants of the system. Our results also yield invariants of continuum fractional quantum Hall states protected by spatial rotational symmetry.

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Ryohei Kobayashi, Yuxuan Zhang, Naren Manjunath, Maissam Barkeshli. 2024-05-27. Crystalline invariants of fractional Chern insulators. https://doi.org/10.1103/8bpm-qbzp

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