title: Strongly spin-orbit coupled two-dimensional electron gas emerging near the surface of polar semiconductors.
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.
authors.affiliation: Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sakano
authors.forename: M S
authors.initials: MS
authors.lastname: Bahramy
authors.forename: A
authors.initials: A
authors.lastname: Katayama
authors.forename: T
authors.initials: T
authors.lastname: Shimojima
authors.forename: H
authors.initials: H
authors.lastname: Murakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kaneko
authors.forename: W
authors.initials: W
authors.lastname: Malaeb
authors.forename: S
authors.initials: S
authors.lastname: Shin
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: H
authors.initials: H
authors.lastname: Kumigashira
authors.forename: R
authors.initials: R
authors.lastname: Arita
authors.forename: N
authors.initials: N
authors.lastname: Nagaosa
authors.forename: H Y
authors.initials: HY
authors.lastname: Hwang
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura
authors.forename: K
authors.initials: K
authors.lastname: Ishizaka