Population inversion and ultrafast terahertz nonlinearity of transient Dirac fermions in Cd${}_3$As${}_2$

Changqing Zhu, Patrick Pilch, Renato M. A. Dantas +7

Harmonic generation provides an efficient tool for the study of ultrafast nonlinear dynamics. We report on time-resolved optical-pump terahertz-harmonic-generation spectroscopic in…