Disentangling bulk and surface Rashba effects in ferroelectric alpha-GeTe

Krempaský, J.; Volfová, H.; Muff, S.; Pilet, N.; Landolt, G.; Radović, M.; Shi, M.; Kriegner, D.; Holý, V.; Braun, J.; Ebert, H.; Bisti, F.; Rogalev, V. A.; Strocov, V. N.; Springholz, G.; Minár, J. and Dil, J. H. (2016): Disentangling bulk and surface Rashba effects in ferroelectric alpha-GeTe. In: Physical Review B, Vol. 94, No. 20, 205111

Abstract

Macroscopic ferroelectric order in alpha-GeTe with its noncentrosymmetric lattice structure leads to a giant Rashba spin splitting in the bulk bands due to strong spin-orbit interaction. Direct measurements of the bulk band structure using soft x-ray angle-resolved photoemission (ARPES) reveals the three-dimensional electronic structure with spindle torus shape. By combining high-resolution and spin-resolved ARPES as well as photoemission calculations, the bulk electronic structure is disentangled from the two-dimensional surface electronic structure by means of surface capping, which quenches the complex surface electronic structure. This unravels the bulk Rashba-split states in the ferroelectric Rashba a-GeTe(111) semiconductor exhibiting a giant spin splitting with Rashba parameter alpha(R) around 4.2 eV angstrom, the highest of so-far known materials.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 2469-9950
• Language: English