17376
2016
eng
7
article
1
2018-12-06
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Spin-texture inversion in the giant Rashba semiconductor BiTeI
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.
Nature Communications
10.1038/ncomms11621
urn:nbn:de:bvb:20-opus-173769
Nature Communications 2016, 7:11621. DOI: 10.1038/ncomms11621
true
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Henriette Maaß
Hendrik Bentmann
Christoph Seibel
Christian Tusche
Sergey V. Eremeev
Thiago R.F. Peixoto
Oleg E. Tereshchenko
Konstantin A. Kokh
Evgueni V. Chulkov
Jürgen Kirschner
Friedrich Reinert
eng
uncontrolled
applied physics
eng
uncontrolled
spintronics
eng
uncontrolled
semiconductors
Elektrizität, Elektronik
open_access
Physikalisches Institut
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/17376/Maass_Nature_Communications.pdf
11946
2014
eng
075013
16
article
1
2015-10-01
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Defect and structural imperfection effects on the electronic properties of BiTeI surfaces
The surface electronic structure of the narrow-gap seminconductor BiTeI exhibits a large Rashba-splitting which strongly depends on the surface termination. Here we report on a detailed investigation of the surface morphology and electronic properties of cleaved BiTeI single crystals by scanning tunneling microscopy, photoelectron spectroscopy (ARPES, XPS), electron diffraction (SPA-LEED) and density functional theory calculations. Our measurements confirm a previously reported coexistence of Te- and I-terminated surface areas originating from bulk stacking faults and find a characteristic length scale of ~100 nm for these areas. We show that the two terminations exhibit distinct types of atomic defects in the surface and subsurface layers. For electronic states resided on the I terminations we observe an energy shift depending on the time after cleavage. This aging effect is successfully mimicked by depositon of Cs adatoms found to accumulate on top of the I terminations. As shown theoretically on a microscopic scale, this preferential adsorbing behaviour results from considerably different energetics and surface diffusion lengths at the two terminations. Our investigations provide insight into the importance of structural imperfections as well as intrinsic and extrinsic defects on the electronic properties of BiTeI surfaces and their temporal stability.
New Journal of Physics
10.1088/1367-2630/16/7/075013
1367-2630
urn:nbn:de:bvb:20-opus-119467
New Journal of Physics 16 (2014) 075013. doi:10.1088/1367-2630/16/7/075013
Sebastian Fiedler
Lydia El-Kareh
Sergey V. Eremeev
Oleg E. Tereshchenko
Christoph Seibel
Peter Lutz
Konstantin A. Kokh
Evgueni V. Chulkov
Tatyana V. Kuznetsova
Vladimir I. Grebennikov
Hendrik Bentmann
Matthias Bode
Friedrich Reinert
eng
uncontrolled
electronic structure
eng
uncontrolled
spin–orbit coupling
eng
uncontrolled
surface morphology
eng
uncontrolled
semiconductor surfaces
Physikalische Chemie
Structure of clean surfaces (and surface reconstruction)
Electronic structure of liquid metals and semiconductors and their alloys
Other nonmetals
Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
Surface states, band structure, electron density of states
Clean metal, semiconductor, and insulator surfaces
open_access
Physikalisches Institut
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/11946/038_Fiedler_New_Journal_of_Physics.pdf