# Entanglement, subsystem particle numbers and topology in free fermion systems.

@article{Zhang2014EntanglementSP, title={Entanglement, subsystem particle numbers and topology in free fermion systems.}, author={Yujie Zhang and Li Sheng and Rui Shen and Rui Wang and Ding-yu Xing}, journal={Journal of physics. Condensed matter : an Institute of Physics journal}, year={2014}, volume={26 10}, pages={ 105502 } }

We study the relationship between bipartite entanglement, subsystem particle number and topology in a half-filled free fermion system. It is proposed that the spin-projected particle numbers can distinguish the quantum spin Hall state from other states, and can be used to establish a new topological index for the system. Furthermore, we apply the new topological invariant to a disordered system and show that a topological phase transition occurs when the disorder strength is increased beyond a…

## 2 Citations

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