Abstract:
We investigate the two-dimensional highly spin-polarized electron accumulation layers commonly appearing near the surface of 𝑛-type polar semiconductors BiTe𝑋 (𝑋 =I, Br, and Cl) by angular-resolved photoemission spectroscopy. Because of the polarity and the strong spin-orbit interaction built in the bulk atomic configurations, the quantized conduction-band subbands show giant Rashba-type spin splitting. The characteristic 2D confinement effect is clearly observed also in the valence bands down to the binding energy of 4 eV. The 𝑋-dependent Rashba spin-orbit coupling is directly estimated from the observed spin-split subbands, which roughly scales with the inverse of the band-gap size in BiTe𝑋.
Citation:
Sakano, M., Bahramy, M. S., Katayama, A., Shimojima, T., Murakawa, H., Kaneko, Y., ... & Ishizaka, K. (2013). Strongly Spin-Orbit Coupled Two-Dimensional Electron Gas Emerging near the Surface<? format?> of Polar Semiconductors. Physical review letters, 110(10), 107204.