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MA: Fachverband Magnetismus

MA 5: Topological insulators: mostly structure and electronic structure (with HL/O/TT)

MA 5.11: Vortrag

Montag, 31. März 2014, 12:15–12:30, POT 051

Oscillatory surface dichroism of the insulating topological insulator Bi₂Te₂Se — •Susmita Basak¹, Madhab Neupane², Hsin Lin¹, N. Alidoust², S.-Y. Xu², Chang Liu², I. Belopolski², G. Bian², J. Xiong², H. Ji³, S. Jia³, S.-K. Mo⁴, M. Bissen⁵, M. Severson⁵, N. P. Ong², T. Durakiewicz⁶, R. J. Cava³, A. Bansil¹, and M. Z. Hasan² — ¹Department of Physics, Northeastern University, Boston, Massachusetts, USA — ²Joseph Henry Laboratory and Department of Physics, Princeton University, Princeton, New Jersey, USA — ³Department of Chemistry, Princeton University, Princeton, New Jersey, USA — ⁴Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, USA — ⁵Synchrotron Radiation Center, Stoughton, Wisconsin, USA — ⁶Condensed Matter and Magnet Science Group, Los Alamos National Laboratory, Los Alamos, New Mexico, USA

We present a study of the effect of angular momentum transfer between polarized photons and topological surface states of the insulating topological insulator Bi₂Te₂Se using circular dichroism-angle resolved photoemission spectroscopy. The photoelectron dichroism demonstrate a dramatic sign flip with the change of photon frequency and we show that this is a consequence of a strong coupling between the photon field and the spin-orbit nature of the initial Dirac states on the surface. Our studies reveal the intrinsic dichroic behavior of topological surface states and point toward the potential utility of bulk insulating topological insulators in opto-spintronics device applications.