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O: Fachverband Oberflächenphysik
O 8: Ultrafast Electron Dynamics at Surface and Interfaces I
O 8.6: Talk
Monday, March 27, 2023, 11:45–12:00, TRE Phy
High-harmonic generation in topological insulator surface states using wave-packet approaches — •Vanessa Junk1, Wolfgang Hogger1, Alexander Riedel1, Cosimo Gorini2, and Klaus Richter1 — 1Institute for theoretical physics, University of Regensburg, Germany — 2Université Paris-Saclay, CEA, CNRS, SPEC, 91191, Gif-sur-Yvette, France
The interaction of matter with strong-field light gives rise to highly non-linear electron dynamics within the material. The electric field of the light accelerates electrons through the band structure and drives non-perturbative transitions, leading to strongly anharmonic electron velocities and the emission of high-order harmonics.
Here, we want to study these electron dynamics for the surface states of topological insulators by solving the time-dependent Schrödinger equation for wave packets. That the separation of bulk and surface high harmonics is experimentally possible has been demonstrated recently [1]. Furthermore, an alternating polarization rotation between odd and even order harmonics was found and attributed to the hexagonal warping present in Bi2Te3 surface states. Using effective Dirac models and taking into account effects of the Fermi sea, we can reproduce these experimental features with our wave-packet approach.
[1] C. Schmid, L. Weigl, P. Grössing, V. Junk, C. Gorini, S. Schlauderer, S. Ito, M. Meierhofer, N. Hofmann, D. Afanasiev, J. Crewse, K. Kokh, O. Tereshchenko, J. Güdde, F. Evers, J. Wilhelm, K. Richter, U. Höfer and R. Huber, Tunable non-integer high-harmonic generation in a topological insulator, Nature 593, 385-390 (2021)