English

Topological meaning of Z$_2$ numbers in time reversal invariant systems

Mesoscale and Nanoscale Physics 2009-11-13 v2

Abstract

We show that the Z2_2 invariant, which classifies the topological properties of time reversal invariant insulators, has deep relationship with the global anomaly. Although the second Chern number is the basic topological invariant characterizing time reversal systems, we show that the relative phase between the Kramers doublet reduces the topological quantum number Z to Z2_2.

Keywords

Cite

@article{arxiv.0809.4532,
  title  = {Topological meaning of Z$_2$ numbers in time reversal invariant systems},
  author = {T. Fukui and T. Fujiwara and Y. Hatsugai},
  journal= {arXiv preprint arXiv:0809.4532},
  year   = {2009}
}

Comments

4 pages, typos corrected