All optical ultrafast probe of a topological phase transition

R. E. F. Silva, Á. Jiménez-Galán, B. Amorim, O. Smirnova, M. Ivanov

Published 2018-06-29Version 1

High harmonic spectroscopy provides fundamental insight into the electronic structure and dynamics of matter. Initially developed as a probe of atomic and molecular targets, it has now begun to shed light onto fundamental properties of condensed matter systems, opening the way for ultrafast optical probing of solid state materials. One of the most fascinating recent developments in condensed matter is the possibility that certain systems can sustain robust chiral edge states, which are protected by topologically invariant quantities of the bulk system. Here we show that high harmonic spectroscopy offers an all-optical probe for the characterization of topologically distinct phases of matter. We use the nonlinear optical response to map out the phase diagram across a topological phase transition in the 2D Chern insulator famously proposed by Haldane. Our work opens a new route for the detection of topological invariants in matter on an ultrafast time-scale.