Ellipticity control of terahertz high-harmonic generation in a Dirac semimetal
Semyon Germanskiy, Renato M. A. Dantas, Sergey Kovalev, Chris Reinhoffer, E. A. Mashkovich, P. H. M. van Loosdrecht, Yunkun Yang, Faxian Xiu, Piotr Surówka, Roderich Moessner, Takashi Oka, Zhe Wang
Abstract
We report on terahertz high-harmonic generation in a Dirac semimetal as a function of the driving-pulse ellipticity and on a theoretical study of the field-driven intraband kinetics of massless Dirac fermions. Very efficient control of the third-harmonic yield and polarization state is achieved in electron-doped ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$ thin films at room temperature. The observed tunability is understood as resulting from terahertz-field-driven intraband kinetics of the Dirac fermions. Our study paves the way for exploiting the nonlinear optical properties of Dirac matter for applications in signal processing and optical communications.