title: Spin-dependent quantum interference in photoemission process from spin-orbit coupled states.
abstract: Spin-orbit interaction entangles the orbitals with the different spins. The spin-orbital-entangled states were discovered in surface states of topological insulators. However, the spin-orbital-entanglement is not specialized in the topological surface states. Here, we show the spin-orbital texture in a surface state of Bi(111) by laser-based spin- and angle-resolved photoelectron spectroscopy (laser-SARPES) and describe three-dimensional spin-rotation effect in photoemission resulting from spin-dependent quantum interference. Our model reveals that, in the spin-orbit-coupled systems, the spins pointing to the mutually opposite directions are independently locked to the orbital symmetries. Furthermore, direct detection of coherent spin phenomena by laser-SARPES enables us to clarify the phase of the dipole transition matrix element responsible for the spin direction in photoexcited states. These results permit the tuning of the spin polarization of optically excited electrons in solids with strong spin-orbit interaction.
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yaji
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Kuroda
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Sogen
authors.initials: S
authors.lastname: Toyohisa
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Harasawa
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Yukiaki
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510, Japan.
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Beijing Center for Crystal Research and Development, Chinese Academy of Science, Zhongguancun, Beijing 100190, China.
authors.forename: Chuangtian
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Physics, Ochanomizu University, Tokyo 112-8610, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Komori
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Shik
authors.initials: S
authors.lastname: Shin