Abstract
We have performed angle-resolved photoemission spectroscopy on TlBiSe2, which is a member of the ternary chalcogenides theoretically proposed as candidates for a new class of three-dimensional topological insulators. We found direct evidence for a nontrivial surface metallic state showing an "X"-shaped energy dispersion within the bulk-band gap. The present result unambiguously establishes that TlBiSe2 is a strong topological insulator with a single Dirac cone at the Brillouin-zone center. The observed bulk-band gap of 0.35eV is the largest among known topological insulators, making TlBiSe2 the most promising material for studying room-temperature topological phenomena.
Original language | English |
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Article number | 136802 |
Journal | Physical review letters |
Volume | 105 |
Issue number | 13 |
DOIs | |
Publication status | Published - 2010 Sep 23 |
ASJC Scopus subject areas
- Physics and Astronomy(all)