Topological Insulators: From equilibrium properties with synchrotron radiation to dynamics with laser excitation

Datum

17.05.2019

Zeit

13:00 - 14:00

Sprecher

Dr. Jaime Sánchez-Barriga

Zugehörigkeit

Helmholtz-Zentrum Berlin für Materialien und Energie, Bessy II

Sprache

en

Hauptthema

Materialien

Host

Beschreibung

In this talk, I will provide an overview of my activity on spin-based phenomena in topological insulators primarily using time-, spin- and angle-resolved photoemission as well as synchrotron-radiation methods. In the first part of the talk, I will concentrate on the spin-dependent properties of topological surface states (TSSs) in equilibrium by highlighting previous and recent results using synchrotron-based photoemission. This includes the manipulation of photoelectron spins using circularly polarized light, the direct observation of magnetic and non-magnetic gaps at the Dirac point of TSSs, and the realization of topological quantum-phase transitions between topological crystalline insulators and topological insulators. In the second part of the talk, I will focus on dynamical aspects such as observation of ultrafast spin-polarized electrical currents, anisotropic coherent-phonon oscillations on topological insulator surfaces or the electron relaxation dynamics near the critical point of a trivial to topological quantum-phase transition. Finally, I will discuss the impact of ultrafast carrier transport on the dynamics of TSSs following laser excitation, and describe how the transient spin textures observed above the Fermi level affect the ultrafast channels of charge and energy transfer that are relevant for the relaxation of carriers.

Links

• Seminars at the IFW

Letztmalig verändert: 24.06.2019, 15:23:05