Abstract: At the heart of the Weyl semimetal are massless, chiral quasiparticles that derive from electronic band-crossings split by either spatial inversion or time-reversal symmetry breaking. The resulting nodal points in the bulk band structure serve as sources and sinks of “topological charge” that are responsible for the phenomenology usually associated with these materials, including open Fermi arc surface states and the chiral anomaly. However, Weyl semimetals with acentric crystal structures can also support second order nonlinear optical responses that reveal characteristics of their band structure in surprising ways. In this talk, I will discuss our work using second harmonic generation and laser-driven currents that uncover distinctive aspects of these topological states, as well as recent experiments that provide evidence for electronic symmetry breaking in a family of structurally chiral Weyl semimetals.
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