Toward ultrafast control of Dirac electrons: Photoexcitation and coherent phonons in topological semimetals

Seminar

  • Datum: 11.02.2020
  • Uhrzeit: 11:00
  • Vortragender: Prof. Christopher P. Weber
  • Department of Physics, Santa Clara University, Santa Clara, U.S.A.
  • Ort: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Saale)
  • Raum: Lecture Hall, B.1.11
Toward ultrafast control of Dirac electrons: Photoexcitation and coherent phonons in topological semimetals

In the newly-discovered Dirac and Weyl semimetals, electrons' dispersions cross masslessly at a node, giving the materials many exotic electronic and optical properties. The ability to controllably open or close a gap at the Dirac node would allow experimenters to manipulate many of the materials' exotic properties at will, and ultrafast control of the node would allow these properties to be turned on or off in a flash. I will describe our efforts to use the vibration of a coherent phonon for sub-picosecond control of the Dirac node in the semimetal SrMnSb2. I will also describe some other physics that can be learned from ultrafast studies of Dirac and Weyl semimetals, including our studies of the thermodynamics and the motion of photo-excited electrons and holes.

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