PME Special Seminar - Alexander Wood

- When:
- Tuesday, March 12, 2024 2:00 pm - 3:00 pm
- Where:
- ERC 201B
- Speaker:
- Alexander Wood, ARC DECRA Fellow, University of Melbourne
- Description:
Seminar: Measuring, mapping, and manipulating photocurrent and dark defects in diamond
In this talk, I will discuss recent experiments in my group where we use the charge state of the nitrogen-vacancy center to detect the flow of photocurrent inside the diamond itself, and where we employ the deleterious environment surrounding NV qubits as quantum sensors in their own right. We image photocurrent by detecting charge state conversion of NV centres, while electrically monitoring the generated photocurrent, which allows us to observe spatiotemporal correlations between the two modalities. Using optical initialization protocols, we can tailor the charge state of nitrogen impurities in the diamond on demand, and observe drastically different photocurrent and images of the current flow, ranging from narrow filaments in a regime dominated by positively-charged nitrogen, to almost ballistic trajectories when the nitrogen is charge neutral. We can use light to engineer conducting channels and space-charge regions ranging from diffraction-limited to hundreds of microns, offering the prospect of reconfigurable, wide bandgap designer optoelectronics. We anticipate our approach might be useful for in-situ characterization of diamond electrical devices, and extended to probe other insulators (e.g., SiC, GaN) relevant to present electronic technologies. I will also discuss our recent work involving P1 centers in diamond, which we use to study their local nuclear spin environment despite being unpolarised sources of noise to the NV central spin. Furthermore, under special rf and microwave control schemes the intrinsic coherence time of the P1 center can be increased, making them potentially useful qubits.
- Contact:
- Mary Pat McCullough, mpm1@uchicago.edu