UROP Proceedings 2022-23

School of Science Department of Physics 67 Quantum Sensing with NV center in Diamond for Many Body Physics Supervisor: YANG, Sen / PHYS Student: HUANG, Xiaotong / PHYS Course: UROP1100, Spring In this project, our purpose is to probe the magnetic properties of the target material with Magneto-optical measurements. Magnetic properties are very important in many fields and research areas. Against this background, finding a way to detect the magnetic exactly becomes a problem. Among many experimental ways to probe the magnetic properties, we choose the magneto-optical method because of its sensitivity, accuracy, and simplicity. For linear polarized light, when it comes through a magnetic material, there will be a rotation in the major polarized axis and change it to elliptic polarization, which we called it Kerr effect. By monitoring the variation of polarization, we can probe the magnetic properties of our sample backward. We use the laser as our light source, construct an optical path to make the light travels through the samples, and monitor it with Red Pitaya. Also, we need to design the program in Red Pitaya to make the measurements automatically and get visualization. Quantum Sensing with NV Center in Diamond for Many Body Physics Supervisor: YANG, Sen / PHYS Student: LI, Hengjian / PHYS Course: UROP1100, Fall UROP3200, Summer Various weak signals can be detected using quantum sensing, which combines a wide range of devices that rely on their quantum properties. It is possible to achieve high accuracy, stability, and resolution with these devices, which is superior to classical approaches. Recently, sensing with 2D material attracts high attention. The class of layered material provide us a chance to probe the physics in a distance of a few atoms. Among which, hBN is selected as a test material for its stability and readiness to be integrated to chips. The project aims to conduct CW ODMR (optically detected magnetic resonance) method to sense the applied magnetic field to demonstrate the sensing ability of spin defects in hBN. Quantum Sensing with NV Center in Diamond for Many Body Physics Supervisor: YANG, Sen / PHYS Student: YU, Qingrong / SSCI Course: UROP1000, Summer Spin defects in hexagonal boron nitride (hBN), a 2D van der Waals material, have shown great prospect in quantum sensing, as well as many other modern quantum technologies. In this report, we demonstrate the mechanism of the negatively charged boron vacancy (VB-) spin defect in hBN, and the experiment settings designed to optimize our results. We first demonstrate the spin properties of a VB- defect and the optical pumping cycle between different energy states. Next, we illustrate the experimental setup for photoluminescence (PL) spectrum and optically detected magnetic resonance (ODMR) measurements. We also discuss the applications of hBN as a quantum sensor, specifically in probing the local electric field signal, which has attracted wide research interest in recent years.