Abstract
First-principles calculations are employed to demonstrate a giant Rashba spin splitting in Bi2Se3:Tl. Biaxial tensile and compressive strain is used to tune the splitting by modifying the potential gradient. The band gap is found to increase under compression and decreases under tension, whereas the dependence of the Rashba spin splitting on the strain is the opposite. Large values of (R) = 1.57 eV angstrom at the bottom of the conduction band (electrons) and (R) = 3.34 eV angstrom at the top of the valence band (holes) are obtained without strain. These values can be further enhanced to (R) = 1.83 eV angstrom and (R) = 3.64 eV angstrom, respectively, by 2% tensile strain. ((c) 2014 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)