Work

Topological electronic structure and Weyl semimetal in the TlBiSe 2 class of semiconductors

Year: 2012

Type: article

Abstract: We present an analysis of bulk and surface electronic structures of thallium-based ternary III-V-VI${}_{2}$ series of compounds TlMQ${}_{2}$, where $\mathrm{M}=\mathrm{Bi}$ or Sb and $\mathrm{Q}=\mathrm{S}$, Se, or Te, using the ab initio density functional theory framework. Based on parity analysis and (111) surface electronic structure, we predict TlSbSe${}_{2}$, TlSbTe${}_{2}$, TlBiSe${}_{2}$, and TlBiTe${}_{2}$ to be nontrivial topological insulators with a single Dirac cone at the $\ensuremath{\Gamma}$ point and TlSbS${}_{2}$ and TlBiS${}_{2}$ to be trivial band insulators. Our predicted topological phases agree well with available angle-resolved photoemission spectroscopy measurements, in particular, the topological phase changes between TlBiSe${}_{2}$ and TlBiS${}_{2}$. Moreover, we propose that Weyl semimetal can be realized at the topological critical point in TlBi(S${}_{1\ensuremath{-}x}$Se${}_{x}$)${}_{2}$ and TlBi(S${}_{1\ensuremath{-}x}$Te${}_{x}$)${}_{2}$ alloys by breaking the inversion symmetry in the layer-by-layer growth in the order Tl-Se(Te)-Bi-S, yielding six Dirac cones centered along the $\ensuremath{\Gamma}$-$L$ directions in the bulk band structure.

Source: Physical Review B

DOI: 10.1103/physrevb.86.115208

Authors: Bahadur Singh, Ashutosh Sharma, H. Lin, M. Z. Hasan, R. Prasad, A. Bansil

Institutions: Indian Institute of Technology Kanpur, Northeastern University, Princeton University

Language: English

Topic: Topological Materials and Phenomena

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green