Self-focusing in nodal semimetals

Abstract

We analyze the Kerr index, associated critical power, and focal length for nodal semimetals in a Weyl, Dirac, and gapped semimetal phase. Our model produces a Kerr index of 10 − 15 − 10 − 20 m 2 / W in the micro-meter wavelength range. Novel dependence of the Kerr index, critical power, and focal length on temperature, chemical potential, bandgap, and node separation are readily obtained through our model and show that the tunability of the non-linear response of a nodal semimetal persists in its focusing phenomenon.