Defence Dates

Nipissing University's School of Graduate Studies is pleased to invite the university community at large, faculty, students and administrators to attend the oral defence of the following student:

William Johnston

Master of Science in Mathematics

Coherent Control of Optical Absorption and the Energy Transfer Pathway of an Infrared Quantum Dot Hybridized with a VO2 Nanoparticle

November 9th, 2:30pm

Room B217, Nipissing University, North Bay


We systematically investigate the optical response of a semiconductor quantum dot (QD) hybridized with a spherical vanadium dioxide nanoparticle (VO2NP) in the infrared (IR) region. The VO2NP features a semiconductor to metal phase change characteristic below and above a critical temperature that leads to an abrupt change in the particle’s optical properties. This feature means that the QD-VO2NP hybrid system can support the coherent coupling of exciton-polaritons and exciton-plasmon polaritons in the semiconductor and metal phases of the VO2NP, respectively. In our calculations, the VO2NP phase transition is modelled with a filling fraction (f), representing the fraction of the VO2NP in the metallic phase. The phase transition is driven by the hybrid system’s interaction with a continuous wave (CW) IR laser field. In this paper, we show how control over the filling fraction results in the enhancement or suppression of the QD’s linear absorption. These variations in the QD absorption is due to dramatic changes in the effective local field experienced by the QD and the non-radiative energy transfer from the QD to the VO2NP. The presented results have the potential to be applied to the design of thermal sensors at the nanoscale. 

Students, faculty, staff and administrators from other Nipissing University campuses who are interested in attending a defence, in person or via videoconference should contact the School of Graduate Studies,​​​​​​​​​​​​​​​​​​​​​​​​​​​ at least one day prior to the defence.​​​​​​​