Nonequilibrium Many-Body Dynamics

Nonlinear response and nonequilibrium dynamics of many-body systems

The nonlinear response of quantum materials contains a wealth of information that is often hidden in the linear regime. Examples include second-harmonic generation (SHG) as a sensitive probe of electronic symmetry and higher-order conductivities that give insight into the quantum geometry and topology of electronic Bloch states in solids. Two-dimensional coherent THz and Raman spectroscopy are two other powerful nonlinear probes of low-energy excitations in quantum materials, which have recently become available in several labs.

Our group performs theoretical research in this direction, both the understand experimental results and to predict new observable phenomena. For example, we have theoretically shown how 2D THz spectroscopy can directly probe fractionalized quasiparticle properties in the Kitaev honeycomb spin liquid and provide evidence for the emergence of localized Majorana excitations trapped by vison pairs. Our group is also interested in post-quench dynamics close to critical points as well as pump-probe spectroscopy of superconductors and their control via nonequilibrium phonons.