Studies of light-matter interaction in quantum confined system have provided great insight into diverse and fundamental problems such as many-body interactions and quantum entanglement. We use and develop a variety of optical spectroscopy tools such as correlated single photon counting, Brillouin light scattering, and multidimensional ultrafast spectroscopy to probe electron dynamics in nanostructures. While we focus on understanding the fundamental physical principles governing the optical response of semiconductor, metallic, and magnetic nanostructures, our research is relevant for applications in opto- electronics, quantum electronics, and quantum information processing.
We are pushing the frontiers of what is detectable and what is controllable in the area of light-matter interaction at the nano-scale. For example, when a single semiconductor quantum dot is excited by light with sufficient energy, it will subsequently decay back to the ground state by emitting a single photon with a high probability. It turns out that one can control of the timing of photon emission by placing a metallic nanoparticle nearby or placing the quantum dot in a photonic crystal fabricated using e-beam lithography. In another example, a single frequency laser incident on a ferromagnetic microstructure may absorb or emit a magnon (quanta of spin waves). The photon will gain or lose a tiny amount of energy. If one can detect the inelastically scattered light, one can learn some very important information about the intrinsic properties of these magnetic structures.
Check out our on-going projects on the “research” and “publication” page. We are always looking for highly motivated graduate and undergraduate students to join the group. Please contact Prof. Li if you are interested.