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arXiv · 1205.3005

Three-dimensional bulk band dispersion in polar BiTeI with giant Rashba-type spin splitting

M. Sakano·J. Miyawaki·A. Chainani·Y. Takata·T. Sonobe·T. Shimojima·M. Oura·S. Shin·M. S. Bahramy·R. Arita·N. Nagaosa·H. Murakawa·Y. Kaneko·Y. Tokura·K. Ishizaka
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Abstract

In layered polar semiconductor BiTeI, giant Rashba-type spin-split band dispersions show up due to the crystal structure asymmetry and the strong spin-orbit interaction. Here we investigate the 3-dimensional (3D) bulk band structures of BiTeI using the bulk-sensitive $h\nu$-dependent soft x-ray angle resolved photoemission spectroscopy (SX-ARPES). The obtained band structure is shown to be well reproducible by the first-principles calculations, with huge spin splittings of ${\sim}300$ meV at the conduction-band-minimum and valence-band-maximum located in the $k_z=\pi/c$ plane. It provides the first direct experimental evidence of the 3D Rashba-type spin splitting in a bulk compound.

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M. Sakano, J. Miyawaki, A. Chainani, Y. Takata, T. Sonobe, T. Shimojima, M. Oura, S. Shin, M. S. Bahramy, R. Arita, N. Nagaosa, H. Murakawa, Y. Kaneko, Y. Tokura, K. Ishizaka. 2012-05-14. Three-dimensional bulk band dispersion in polar BiTeI with giant Rashba-type spin splitting. https://doi.org/10.1103/physrevb.86.085204

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