The innovation engine for new materials

Kyle Curlett

University: 

University of California, Santa Barbara

Major: 

Math and Physics

Site Abroad: 

Tyndall National Institute, Ireland

Mentor(s): 

Stefan Schulz

Faculty Sponsor(s): 

Eoin O’Reilly

Project Title: 

ON THE ENERGY EIGENVALUES AND EIGENSTATES OF QUANTUM DOTS

Project Description: 

Quantum dots have a large range of applications in the modern world, including photovoltaic devices, lasers, quantum computing, and cellular imaging. Recent experiments have shown that (1,1,1) oriented quantum dots do not always have optical splitting. This equivalent to not having any p-state splitting, meaning the first and second excited states have the same energy. Quantum dots without this are useful for entangled photon emission, with a variety of applications. The goal of this project is to determine how alloy contamination affects p-orbital splitting in both (0,0,1) oriented and (1,1,1) oriented GaAs-InAs quantum dots. To do this the first step was to model the band structure for InAs and GaAs (how the potential changes as one moves through the substance). Because we did not have experimental data for all the parameters, we needed to match this to experimental data as it was made. It was then possible to model the actual quantum dots. I updated existing code that modeled a (0,0,1) dot. The existing code was updated to allow the user more freedom in choosing parameters, and to give more accurate results. The p-state splitting as a function of the size of the dot was then examined, but alloy contamination has not been examined yet. After examining the energies of the (0,0,1) quantum dots I then created a (1,1,1) system. In this system the p-state splitting was not zero as expected. This implies that there are problems in the code. Attempts at fixing this problem are still ongoing.