Large spin splitting of metallic surface-state bands at adsorbate-modified gold/silicon surfaces

Abstract

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.-- et al. ; Finding appropriate systems with a large spin splitting of metallic surface-state band which can be fabricated on silicon using routine technique is an essential step in combining Rashba-effect based spintronics with silicon technology. We have found that originally poor structural and electronic properties of the Au/Si(111) √3x√3 surface can be substantially improved by adsorbing small amounts of suitable species (e.g., Tl, In, Na, Cs). The resultant surfaces exhibit a highly-ordered atomic structure and spin-split metallic surface-state band with a momentum splitting of up to 0.052 Å−1 and an energy splitting of up to 190 meV at the Fermi level. The family of adsorbate-modified Au/Si(111) √3x√3 surfaces, on the one hand, is thought to be a fascinating playground for exploring spin-splitting effects in the metal monolayers on a semiconductor and, on the other hand, expands greatly the list of material systems prospective for spintronics applications. ; Part of this work was supported by the Russian Foundation for Basic Research (Grant Nos. 11-02-98515r, 12-02-00416, 12-02-00430 and 12-02-31745), the Ministry of Education and Science of the RF (Grant Nos. 8022, 8581, 2.8575.2013 and 2.1004.2011), NSh-774.2012.2, the Basque Country Government, Departamento de Educación, Universidades e Investigación (Grant No. IT-366-07), the Spanish Ministerio de Ciencia e Innovación (Grant No. FIS2010-19609-C02-00), German-Russian Interdisciplinary Science Center (G-RISC) funded by the German Federal Foreign Office via the German Academic Exchange Service (DAAD) and Helmholtz Zentrum Berlin fur Materialien und Energie for support within a bilateral Program ''Russian-German Laboratory'' at BESSY-II. We thank S.S. Tsirkin for help with graphical presentation of results. D.U. and A.F. acknowledge support from SPbU grant. ; Peer reviewed