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O: Fachverband Oberflächenphysik
O 84: Electronic Structure of Surfaces I: Spectroscopy, Surface States
O 84.4: Talk
Thursday, March 21, 2024, 11:15–11:30, MA 144
Surface atomic and electronic structure of multiferroic GeTe(111) — •Martin Heinrich1,2, Juraj Krempasky1, Gunther Springholz3, and Matthias Muntwiler1,2 — 1Paul Scherrer Institute, Photon Science Division, 5232 Villigen PSI, Switzerland — 2Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland — 3Institute of Semiconductor Physics, Johannes Kepler University Linz, 4040 Linz, Austria
Multiferroic materials combine multiple coupled ferroic orders in the same system which could be used to bridge the gap between traditional electronics and spintronics. GeTe is a IV-VI semiconductor with multiple existing applications in optoelectronics and thermoelectrics. It recently gained renewed attention due to the discovery of a large Rashba spin splitting in both bulk and surface states that couples to the ferroelectric polarization. A detailed study of its surface atomic and electronic structure is therefore of high relevance towards a deeper, atomic scale understanding of the relevant interactions.
In this contribution, we discuss synchrotron based photoelectron diffraction (XPD, PhD) data combined with multiple scattering calculations, which indicate a contracted surface layer structure of GeTe(111) compared to its bulk structure. Additionally, scanning tunneling microscopy (STM) measurements reveal triangular island growth and a hexagonal atomic surface structure. dI/dV spectroscopy probes the local density of states, which we compare to spatially averaged photoelectron spectra. We identify the Rashba split surface states and resolve their spatial distribution.
Keywords: Multiferroics; Rashba; XPD; STM