A fine point on topological insulators
DOI: 10.1063/1.4796321
Qi and Zhang reply: The letter by Manuel Cardona raises two issues regarding our Physics Today article. The first one concerns the microscopic origin of the band inversion in mercury telluride. It arises both from the spin-orbit splitting of the p orbitals and from the lowering of the s orbital by the so-called Darwin term, which also arises from the relativistic Dirac equation. Because of the article’s space limitations, we discussed only the first mechanism. Regardless of the microscopic origin of the band inversion, the general conclusion of topological edge states in HgTe is unchanged.
The second issue Cardona raises concerns the similar phenomenon in α-tin, which has been discussed extensively in the theory literature about topological insulators. 1 Unfortunately no experiments seeking this phenomenon in α-tin have been carried out to our knowledge.
References
1. See, for example, S. Murakami, N. Nagaosa, S. -C. Zhang, Phys. Rev. Lett. 93, 156804 (2004).
More about the authors
Shou-Cheng Zhang, 1(sczhang@stanford.edu).
Xiao-Liang Qi, 2 Stanford University Stanford, California, US .
