Driven Dirac Materials

Condensed Matter Seminars

Speaker: Sasha Balatsky, Los Alamos National Laboratory
Date & Time: November 4, 2016 12:00 - 1:00
Location: Hennings 318
Local Contact: Marcel Franz/Ian Affleck
Intended Audience: Graduate

*Note this seminar will be on Friday, November 4 from 10:00 – 11:00, off of the usual Condensed Matter Seminar Series schedule.

Recent pump-probe experiments demonstrate the possibility that Dirac materials(DMs) may be driven into transient excited states describable by the state with two separate inverted occupancies, one for the electrons and one for the holes. Given the Dirac nature of the spectrum, such an inverted population allows the optical tunability of the density of states (DOS) of the electrons and holes, effectively offering control of the strength of the Coulomb interaction in a pumped DM. I will discuss the feasibility of realizing transient excitonic instabilities in optically-pumped DMs. I willdemonstrate the tunability of the effective coupling constant and identify signatures of the transient excitonic condensate. Furthermore, I will discuss the guidelines for experiments by both identifying the regimes in which such exotic many-body states are more likely to be observed and estimating the magnitude of the excitonic gap for a few important examples of DM and Weyl materials intwo and three- dimensions.