Biograph: Dr Xiulai Xu received BA degree in Electronic Engineering from the Jilin University in 1996, and Ph.D. degree from Cavendish Laboratory, University of Cambridge in 2005. He has been working as research scientist, senior research scientist in Hitachi Cambridge Laboratory from 2005-2011, and was also a research fellow in Clare Hall, University of Cambridge during 2009-2011. He is currently a professor with Institute of Physics, Chinese Academy of Sciences on quantum optoelectronics and nano-photonics

Title: Manipulating the coupling strength in a strongly coupled quantum dot-cavity system

Abstract: We report on high-resolution photocurrent (PC) spectroscopies of a single self-assembled InAs/GaAs quantum dot (QD) embedded in an n-i-Schottky device. For a positive charged trions (X+) in a single quantum dot, giant enhancement of photocurrent has been achieved because of the Coulomb repulsion between the two holes. Furthermore, strong coupling for cavity QED between different excitonic states in a single quantum dot and the cavity will be presented with a two-photon Rabi splitting. Both exciton and biexciton transitions couple to a high quality factor photonic crystal cavity with large coupling strengths over 130 μeV. Finally, strong interactions between cavities and p-shell excitons with a great enhancement by the in situ wave-function control will be demonstrated because of the large wave-function extents and nonlocal interactions beyond the dipole approximation with a large coupling strength of 210 eV being achieved.