title: Spin-texture inversion in the giant Rashba semiconductor BiTeI.
abstract: Semiconductors with strong spin-orbit interaction as the underlying mechanism for the generation of spin-polarized electrons are showing potential for applications in spintronic devices. Unveiling the full spin texture in momentum space for such materials and its relation to the microscopic structure of the electronic wave functions is experimentally challenging and yet essential for exploiting spin-orbit effects for spin manipulation. Here we employ a state-of-the-art photoelectron momentum microscope with a multichannel spin filter to directly image the spin texture of the layered polar semiconductor BiTeI within the full two-dimensional momentum plane. Our experimental results, supported by relativistic ab initio calculations, demonstrate that the valence and conduction band electrons in BiTeI have spin textures of opposite chirality and of pronounced orbital dependence beyond the standard Rashba model, the latter giving rise to strong optical selection-rule effects on the photoelectron spin polarization. These observations open avenues for spin-texture manipulation by atomic-layer and charge carrier control in polar semiconductors.
authors.affiliation: Experimentelle Physik VII, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Henriette
authors.initials: H
authors.lastname: Maaß
authors.affiliation: Experimentelle Physik VII, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bentmann
authors.affiliation: Experimentelle Physik VII, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Seibel
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Tusche
authors.affiliation: Institute of Strength Physics and Materials Science, 634055 Tomsk, Russia.|Tomsk State University, 634050 Tomsk, Russia.|Saint Petersburg State University, 198504 Saint Petersburg, Russia.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Eremeev
authors.affiliation: Experimentelle Physik VII, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Thiago R F
authors.initials: TR
authors.lastname: Peixoto
authors.affiliation: Saint Petersburg State University, 198504 Saint Petersburg, Russia.|Institute of Semiconductor Physics, 636090 Novosibirsk, Russia.|Novosibirsk State University, 636090 Novosibirsk, Russia.
authors.forename: Oleg E
authors.initials: OE
authors.lastname: Tereshchenko
authors.affiliation: Saint Petersburg State University, 198504 Saint Petersburg, Russia.|Novosibirsk State University, 636090 Novosibirsk, Russia.|Institute of Geology and Mineralogy, 630090 Novosibirsk, Russia.
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Kokh
authors.affiliation: Tomsk State University, 634050 Tomsk, Russia.|Saint Petersburg State University, 198504 Saint Petersburg, Russia.|Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Basque Country, Spain.|Departamento de Física de Materiales and Centro Mixto CSIC-UPV/EHU, Facultad de Ciencias Qumicas, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Apdo. 1072, 20080 San Sebastián/Donostia, Basque Country, Spain.
authors.forename: Evgueni V
authors.initials: EV
authors.lastname: Chulkov
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kirschner
authors.affiliation: Experimentelle Physik VII, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Reinert