Hosting of surface states in spin–orbit induced projected bulk band gaps of W(1 1 0) and Ir(1 1 1). (24th May 2017)

• Record Type: Journal Article
• Authors: Elmers, H J; Kutnyakhov, D; Chernov, S V; Medjanik, K; Fedchenko, O; Zaporozhchenko-Zymakova, A; Ellguth, M; Tusche, C; Viefhaus, J; Schönhense, G
• Is Part Of: Journal of physics. Volume 29:Number 25(2017)
• Publication Date: 2017-05-24
• Subjects: photoelectron spectroscopy -- ARPES -- momentum time-of-flight microscopy -- soft x-ray; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aa7173
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Spin-momentum locking of surface states has attracted great interest in recent years due to envisioned technological applications in the field of spintronics. Normal metal surfaces like W(1 1 0) and Ir(1 1 1) show surface states with energy dispersions and spin-polarization textures, which are reminiscent of topologically non-trivial surface states. In order to understand this phenomenon the connection of bulk and surface states has to be explored. Using time-of-flight momentum microscopy with soft x-ray excitation, we present a comprehensive analysis of the bulk bands of W and Ir. Surface states are determined by the same method with photon excitation in the vacuum ultraviolet region. The superposition of both spectral densities reveals the hosting of surface states within the gap structure of bulk bands projected on the surface Brillouin zone. Quantitative differences in the extension of experimental and theoretical local band gaps indicate an underestimation of electron correlation effects in theory.