I work on condensed matter theory in close collaboration with experimentalists. I am interested in analytical understanding of interacting electrons in nanoscale devices, with a focus on their collective excitations, optical properties and nonequilibrium processes.
Nonequilibrium phenomenon is everywhere, with you as a good example. People are far from understanding you as a complex dynamical system, just like physicists are far from understanding the nonequilibirum processes of many electron systems. Experimentally, people can use ultrashort (femtosecond~picosecond) light pulses to push the system away from equilibrium, inducing an "ultrafast" dynamics. This dynamics is a vanguard of condensed matter physics, flourished by pump-probe experiments but lacking good theories. Nanoscale materials (graphene and other 2D materials, superconductor flakes, etc.) are popular hosts of these many electron systems, and may enter our future cell phones as devices working at ultrafast time scales. I study the non-equilibrium processes and collective modes in these materials which can often be driven by light.