Decay length of surface-state wave functions on Bi(1 1 1). (10th November 2016)

• Record Type: Journal Article
• Authors: Ishida, H
• Is Part Of: Journal of physics. Volume 29:Number 1(2017)
• Publication Date: 2016-11-10
• Subjects: surface state -- Rashba spin-splitting -- complex band structure -- density functional theory -- embedding method; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/29/1/015002
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We calculate the decay length in surface normal direction of the surface-state wave functions on a clean Bi(1 1 1) surface as a function of two-dimensional (2D) wave vector k along the Γ ̄ − M ̄ line. For this purpose, we perform a first-principles density functional theory (DFT) calculation for semi-infinite Bi(1 1 1) by employing the surface embedded Green's function technique. The decay length of the two surface bands is found to be ̃24 Bi bilayers at M ̄, while it remains less than 5 Bi bilayers when k is away from M ̄ and Γ ̄ . At Γ ̄, the degenerate surface bands are split from the upper boundary energy of the projected bulk valence bands only by 5 meV. In spite of this, the decay length of these bands at Γ ̄ is less than 10 Bi bilayers due to the large effective mass (small curvature) of the highest valence band in the surface normal direction.