Berlin 2015 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 8: Transport: Spintronics and magnetotransport (TT with HL)
HL 8.5: Talk
Monday, March 16, 2015, 10:30–10:45, A 053
Observation of spatial fluctuations of the Rashba parameter by scanning tunneling spectroscopy — •Jan Raphael Bindel1, Marcus Liebmann1, Jascha Ulrich2, Eugene Sherman3, and Markus Morgenstern1 — 1II. Institute of Physics B, RWTH Aachen University, Aachen, Germany — 2Institute for Quantum Information, RWTH Aachen University, Aachen, Germany — 3Basque Foundation for Science, Ikerbasque, Bilbao, Spain
We investigate a 2DES induced by Cs surface doping of p-type InSb(110) and evaluate the Rashba parameter on the local scale. The Rashba effect is one of the possibilities to manipulate spins by external gate voltages which led to the proposal of the spin transistor. As a local property, however, the Rashba effect is prone to disorder as ubiquitous in semiconductors, which, in turn, induces spatial fluctuations of the strength of the Rashba effect, and, thus, spin dephasing [1]. Recently, we have shown that the Rashba effect can be probed by STS in magnetic fields as an additional contribution to the spin splitting [2]. Here, we investigate the correlations between the electrostatic potential and the Rashba effect on the local scale. A detailed magnetic field dependence analysis of the spin splitting is required in order to disentangle the Rashba parameter from the Zeeman effect and the spatially fluctuating exchange enhancement. Moreover the nodal structure of the wave functions has to be considered in higher Landau levels, where it leads to multiple peak structures [3].
[1] Glazov et al., Physica E 42, 2157 (2010).
[2] Becker et al., PRB 81, 155308 (2010).
[3] Hernangómez-Pérez et al., PRB 88, 245433 (2013).