Condensed Matter/Materials & Biological Physics Seminar with Shiyuan Gao on Excitons and Single Phonon Emitters

There is growing interest in the search for better solid state single photon emitters (SPEs), an area where condensed matter physics meets quantum information science. In this talk, I will present two works related to SPEs in two-dimensional (2D) materials. First, I will discuss the quest for identifying the atomic structure of SPEs in hexagonal boron nitride. I will give a brief overview of different levels of first-principle methods that are available to tackle this problem, introduce a computational framework that combines them using Bayesian inference and concepts from statistical physics, and then talks about the results and findings so far. Second, I will discuss the crossover of the radiative properties between in 0D and 2D for an exciton confined in a finite region of 2D material, which is related to the concept of superradiance from quantum optics. This leads to a theoretical upper limit for the brightness of the exciton as a SPE, which is notably enhanced by the non-parabolic exciton dispersion in the 2D limit and goes well beyond typical defect-bound SPEs.