Atomic resolution imaging of quantum spin defects in two dimensional materials

Optical spin defects in wide bandgap materials form the basis of spin qubits for quantum technologies, such as optical networks, computing and sensing. Recently, it has emerged that two dimensional materials, namely hexagonal boron nitride (hBN), host single-photon emitting point defects with optically detected spin signatures. Remarkably, these defects show strong, high purity single-photon emission and microsecond spin coherence, even at room temperature, revealing a promising new material platform for developing scalable quantum devices that operate at ambient conditions. 

It is important to determine the precise atomic structure of hBN single photon defects in order to develop our understanding of their fundamental photophysics, as well as form routes towards deterministic fabrication. Theoretical modeling combined with experimental optical measurements have identified candidate structures but without direct imaging, accurate assignment cannot be conclusive.

Recent developments in transmission electron microscopy (TEM) now offer multi-dimensional approaches to probe the atomic structure of these defects. In this project, the candidate will perform some of the first high-resolution electron microscopy on hBN materials with quantum spin defects, to identify the defect atomic structure. The candidate will work across the Department of Materials (Prof. Stern and Prof. Nicholls) and Diamond Light Source (Dr. Allen) to image the 2D materials with a range of cutting-edge electron microscopy techniques. The ultimate goal is correlation of optical maps of the hBN defects with high resolution imaging of the atomic structure. If successful, this project will pave the way for the deterministic formation of defects and coupling to devices, and have wide ranging implications for development of quantum devices based on defects in 2D materials.  

Image: ACS Nano 2018, 12, 8, 7721–7730