1111.5730 (K. Kuroda et al.)

Experimental verification of PbBi$_{2}$Te$_{4}$ as a 3D topological
insulator    [PDF]

K. Kuroda, H. Miyahara, M. Ye, S. V. Eremeev, Yu. M. Koroteev, E. E. Krasovskii, E. V. Chulkov, S. Hiramoto, C. Moriyoshi, Y. Kuroiwa, K. Miyamoto, T. Okuda, M. Arita, K. Shimada, H. Namatame, M. Taniguchi, Y. Ueda, A. Kimura

The first experimental evidence is presented of the topological insulator state in PbBi$_{2}$Te$_{4}$. A single surface Dirac cone is observed by angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. Topological invariants $\mathbb{Z}_2$ are calculated from the {\it ab initio} band structure to be 1; (111). The observed two-dimensional iso-energy contours in the bulk energy gap are found to be the largest among the known three-dimensional topological insulators. This opens a pathway to achieving a sufficiently large spin current density in future spintronic devices.

View original: http://arxiv.org/abs/1111.5730