Photoemission Circular Dichroism and Spin Polarization of the Topological Surface States in Ultrathin Bi2Te3 Films

Abstract

Circular dichroism (CD) observed by photoemission, being sensitive to the orbital and spin angular momenta of the electronic states, is a powerful probe of the nontrivial surface states of topological insulators, but the experimental results thus far have eluded a comprehensive description. We report a study of Bi2Te3 films with thicknesses ranging from one quintuple layer (two-dimensional limit) to twelve layers (bulk limit) over a wide range of incident photon energy. The data show complex variations in magnitude and sign reversals, which are nevertheless well described by a theoretical calculation including all three photoemission mechanisms: dipole transition, surface photoemission, and spin-orbit coupling. The results establish the nontrivial connection between the spin-orbit texture and CD.

16 pages, 4 figures

References in corpus (4)

• Three dimensional topological invariants for time reversal invariant Hamiltonians and the three dimensional quantum spin Hall effect
• First Principles Studies on 3-Dimentional Strong Topological Insulators: Bi2Te3, Bi2Se3 and Sb2Te3
• Spin Polarization of Photoelectrons from Topological Insulators
• Circular dichroism in angle-resolved photoemission spectroscopy of topological insulators

Cited by in corpus (5)

• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Computational Framework for Angle-Resolved Photoemission Spectroscopy
• Surface Charge Induced Dirac Band Splitting in a Charge Density Wave Material (TaSe4)2I
• Layer and orbital interference effects in photoemission from transition metal dichalcogenides
• Ultrafast Evolution of Bulk, Surface and Surface Resonance States in Photoexcited Bi${}_2$Te${}_3$