Presenter: Yuan Ping (University of California Santa Cruz)
Topic: Excited States and Spin Dynamics for Quantum Defects in Two-dimensional Materials
Time: 9:00 AM, Jul. 31th (Friday)
Zoom Meeting Link:
Zoom ID: 456 862 1540
Spin defects in two-dimensional (2D) materials such as ultrathin hexagonal boron nitride have been found to be promising single-photon emitters and potential candidates for qubits. However, first-principles prediction of accurate defect properties in 2D materials remains challenging, mainly because of the highly anisotropic dielectric screening and strong many body interactions. This work shows how we solve the numerical convergence issues for charged defect properties in 2D materials at both the DFT and many body perturbation theory (GW/Bethe-Salpeter equation), and how we tackle the complex many body interactions including electron-electron, electron-phonon and defect-excitons for the excited state dynamics of spin defects in 2D materials. Recently we developed first-principles spin dynamics through Lindblad dynamics for open quantum systems with couplings with environments, which can accurately predict spin lifetime for general materials. With our methods, we will design spin defects that have deep defect levels, weak electron-phonon coupling, high radiative recombination rates, and long spin relaxation and coherence time as future materials platforms for quantum technologies.
Yuan Ping received her B.Sc. degree in Chemical Physics from University of Science and Technology of China, China, in 2007 and her Ph.D. in theoretical materials chemistry from University of California, Davis under the supervision of Giulia Galli (currently at U. Chicago) in 2013. She was a materials postdoctoral fellow in the DOE energy hub Joint Center for Artificial Photosynthesis at California Institute of Technology from 2013 to 2016, under the supervision of William Goddard III. In 2016, she joined the faculty at UC Santa Cruz as an assistant professor in Chemistry department and affiliated professor in physics department. Ping’s recent research interests focus on first-principles methodology development on excited-state properties for solids and nanostructures, in particular, from many-body perturbation theory with improved numerical efficiency and accuracy, spin and exciton dynamics in low-dimensional systems for quantum information science, and dopants’ effect on small polaron conduction in transition metal oxides. Ping has authored more than 40 high impact peer-reviewed publications and she is a recipient of the Hellman Fellowship at 2018.
Group website: http://yuanping.chemistry.ucsc.edu/
Contact: Tao Cheng
Editor: Ming Lu