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arXiv · 1501.07031

Disentangled topological numbers by a purification of entangled mixed states for non-interacting fermion systems

T. Fukui·Y. Hatsugai
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Abstract

We argue that the entanglement Chern number proposed recently is invariant under the adiabatic deformation of a gapped many-body groundstate into a {\it disentangled/purified} one, which implies a partition of the Chern number into subsystems (disentangled Chern number). We generalize the idea to another topological number, the Z$_2$ Berry phase for a system with particle-hole symmetry, and apply it to a groundstate in a weak topological phase where the Chern number vanishes but the groundstate nevertheless has edge states. This entanglement Berry phase is especially useful for characterizing random systems with nontrivial edge states.

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T. Fukui, Y. Hatsugai. 2015-03-10. Disentangled topological numbers by a purification of entangled mixed states for non-interacting fermion systems. https://doi.org/10.7566/jpsj.84.043703

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