- 著者
- Fukui Takahiro Hatsugai Yasuhiro
- 出版者
- American Physical Society
- 雑誌
- Physical review B (ISSN:10980121)
- 巻号頁・発行日
- vol.75, no.12, pp.121403, 2007-03
- 被引用文献数
- 97 54
For generic time-reversal-invariant systems with spin-orbit couplings, we clarify a close relationship between the Z2 topological order and the spin Chern number (SChN) in the quantum spin-Hall effect. It turns out that a global gauge transformation connects sectors with different SChNs (even integers) modulo 4, which implies that the SChN and Z2 topological orders yield the same classification. We present a method of computing the SChN and demonstrate it in single and double planes of graphene.