Optical Microcavities: A Platform to Manipulate Strong Light-Matter Interactions by Prof Qihua Xiong

Join us in the IAS STEM Graduate Colloquium by Prof Qihua Xiong from Tsinghua University.

About the talk

Optical microcavities are photonic structures that confine light within wavelength-scale volumes, such as distributed Bragg reflectors, photonic crystals, microspheres, or ring resonators. They offer versatile platform to investigate and manipulate light-matter interactions. In the weak-coupling regime, the spontaneous emission rate will be modulated by the Purcell effect, facilitating technological applications in low-threshold lasers, efficient nonlinear processes, and ultra-sensitive biosensors. In the strong-coupling regime, a quantum superposition between photonic state and matter-wave excitation will be resulted, enabling diverse quantum information applications. In this talk, we will discuss our recent effort in manipulating exciton polariton condensates at room temperature in halide perovskite or two-dimensional semiconductor microcavities.

We discuss how we can use optical lattices to engineer the strong optical responses including topological properties, and their ultrafast propagation. Finally, we will briefly discuss the strong nonlinear interactions in polaritons which drives coherent long-range propagation, manifested as optical spin Hall effect and ultrafast functional polaritonic devices. The future directions towards quantum functionality based on polaritons will be discussed in a perspective way.

About Our Speaker

Qihua Xiong, Professor of Physics and Associate Chair of Physics Department at Tsinghua University, APS/MRS/OSA Fellows. He obtained his Ph.D. degree from Penn State University in 2006, and then pursued three years postdoctoral training at Harvard University. He started his independent career as Nanyang Assistant Professor at Nanyang Technological University in 2009, then tenured in 2014 and promoted to full professor in 2016.

He relocated to Tsinghua University in 2020. He was awarded Singapore National Foundation NRF Fellowship in 2009 and NRF Investigatorship in 2014, he received Nanyang Award for Research Excellence in 2014, IPS Nanotechnology Physics Award in 2015, and IUMRS Mid-career Researcher Award in 2024. His scientific research impact was recognised by Clarivate highly cited researchers worldwide (2019-2024). His research covers a wide range of topics related to the fundamental optical processes in low-dimensional quantum materials, and their enhanced light-matter interactions in microcavities.

He has published more than 350 papers in well-established journals and attracted more than 35,000 citations, with an H-index of 103. Currently, he serves as the associate editor for Nano Letters and advisory board for a number of international journals.