title: Tunable spin polarization in bismuth ultrathin film on Si(111).
abstract: We performed a spin- and angle-resolved photoemission spectroscopy of bismuth ultrathin film on Si(111) with various film thickness d. We found that the spin polarization of spin-split Rashba surface states near the Brillouin-zone boundary, which is high (0.7) at d = 40 BL (bilayers), is gradually reduced on decreasing d and almost vanishes at d = 8 BL. This finding provides a novel method to generate spin-polarized electrons with tunable spin-polarization.
authors.affiliation: Department of Physics, Tohoku University, Sendai 980-8578, Japan. a.takayama@arpes.phys.tohoku.ac.jp
authors.forename: Akari
authors.initials: A
authors.lastname: Takayama
authors.forename: Takafumi
authors.initials: T
authors.lastname: Sato
authors.forename: Seigo
authors.initials: S
authors.lastname: Souma
authors.forename: Tamio
authors.initials: T
authors.lastname: Oguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Takahashi