UROP Proceedings 2022-23

School of Science Department of Physics 65 Diffusion of Nanoparticles in a Potential Energy Landscape Supervisor: WONG, Michael Kwok Yee / PHYS Student: CHEUNG, Ho Tin / PHYS Course: UROP1100, Fall UROP2100, Spring UROP3200, Summer In previous semesters, we analyzed the lifetime distribution of nanoparticles in a potential energy landscape with some approximations. This semester, we tried a new approach to compute the lifetime distribution in a square well with transfer matrices. The new approach enabled us to include more possible pathways the particle to reach the survival boundary and turned out the result agrees very well with the simulation result. Aside from theoretical modelling, we have also executed Gillespie Algorithm for diffusion of nanoparticles in 2D. We found that lifetime distribution with certain parameters is identical to the dwell time, which accounts for the time the particle stays in the well. Prediction of Holding Pattern Counts for the Hong Kong International Airport Supervisor: WONG, Michael Kwok Yee / PHYS Student: FU, Yixuan / SENG Course: UROP1100, Summer Using the FlightRadar24 data during 2017 and 2018 for flights to the Hong Kong International Airport (HKIA), we predict the count of holding patterns for each of the direction of approach and their total in a certain time interval (one hour) based on the extracted features in the last time interval: the number of flights that entered the holding area, the number of flights that stayed in the holding area but have not landed, and the number of holding pattern loops. The algorithm we use is XGBoost. The prediction result shows that there is a strong correlation between the count of the holding patterns and the input data, although the model still needs to be improved for higher accuracy. Quantum Computing Based on NV Center in Diamond Supervisor: YANG, Sen / PHYS Student: FEI, Zijian / PHYS Course: UROP2100, Fall UROP3100, Spring In this project, we are supposed to use a room temperature experimental setup to detect the charge state of the NV color center. The NV center is a kind of crystal defect in diamond formed by two lattice defects, a nitrogen atom and a vacancy. The NV color center can be in NV0 or NV - states, and NV - is used for quantum calculation. Therefore, in order to improve the quantum fidelity, we need to make a measurement and selection, and select the one only in NV - state. This is done by illuminating it with a 593nm laser and detecting the fluorescence intensity. We need to tune the 593nm laser, use AOM (acousto-optic modulator) to switch the laser on and off, and record the fluorescence count. We also need to optimize the parameters in our work.