Thursday, February 28, 20192:00 PM - 3:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Observing topological phases and transitions with high harmonic generation
Alexis A. ChaconT-1/CNLS
Topological materials are of interest to both fundamental sciences and advanced technologies, because topological states are robust withrespect to perturbations and dissipation. Experimental detection of topological invariants is thus in great demand, but is extremelychallenging. Ultrafast laser-matter interactions, and in particular high-harmonic generation (HHG), were proposed several years ago as tools to explore the structural and dynamical properties of various matter targets. Here, in this talk I will show that the low and high harmonic orders of the HHG spectrum along the parallel and perpendicular emission components with respect to a linearly-polarized laser-field can be used as a signature of topological phase transitions in the paradigmatic Haldane model. We find evidence to show that even and odd harmonics as well as theiremitted intensities are sensitive to crossing a topological phase boundary in a medium with broken inversion and time-reversal symmetries. Our findings pave the way to understand fundamentalquestions about the ultrafast electron-hole pair dynamics in topological materials via HHG.
Host: David Metiver