Nonlinear Spectroscopy

Nonlinear optical responses probe subtle changes in symmetry, quantum geometry, and enable novel light generation and sensing devices. Our group is developing 3rd order nonlinear photocurrent techniques better to probe the symmetry and quantum geometry of various materials as they are tuned into novel phases. We aim to develop spectroscopic techniques to understand the material properties and device designs that enhance nonlinear responses for devices and the proper conditions to use nonlinear responses to understand emergent phases of matter better. The nonlinear photocurrent setup has multiple lasers ranging from 100 meV to 2.3 eV, polarization optics to enable full polarization control, cryostats to enable studies across a range of temperatures and magnetic fields.

Relevant Papers:

Topology and geometry under the nonlinear electromagnetic spotlight Nature materials 20, 1601 (2021)

Colossal mid-infrared bulk photovoltaic effect in a type-I Weyl semimetal Nature materials 18, 471 (2019)