# 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
}
}
• Y. Zhang, +2 authors D. Xing
• Published 3 November 2011
• Physics, Medicine
• Journal of physics. Condensed matter : an Institute of Physics journal
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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