Deterministic Creation and Annihilation of Point Defects in 2D Materials Utilizing Electron and Ion Beam Irradiation

Deterministic creation of quantum emitters has long been a topic of study for quantum information science (QIS). It is also indispensable to develop techniques enabling deterministic annihilation of vacancy-center quantum emitters. In this work, we utilize irradiation modes of both e-beam and ion beam to introduce point defects in a monolayer of both MoSe₂and h-BN. An aberration corrected transmission electron microscope (TEM) enables observations with time-resolved atomic-resolution imaging, including dynamic creation and annihilation of defect sites in the monolayer. In situ high-resolution TEM reveals that the annihilation of vacancy clusters using the electron beam can be achieved with an optimal electron beam dose rate. In-situ annealing of irradiated samples has been explored to understand the formation mechanism of desired quantum emitters. Coupled with ex-situ photoluminescence, these approaches allow us a detailed study of the deterministic quantum emitter creation and the correlation with their optical behaviors in 2D materials.<br/><br/>Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The correlation of point defects with optical behaviour is supported by QIS research funding from the U.S. Department of Energy, Office of Science User Facility. Ion irradiation was performed in IVEM-Tandem Facility at Argonne National Laboratory.