Andrew Williamson

Education:

Ph.D. Quantum Monte Carlo Calculations of Electronic Excitations,
         Theory of Condensed Matter Group, Cavendish Laboratory, Cambridge University, UK
M.A. Physical Natural Sciences, Cambridge University, UK

Research:

My research interests are centered on calculating the electronic structure of semiconductor materials. My Ph.D. involved in developing the quantum Monte Carlo (QMC) technique for performing highly accurate calculations of exchange and correlation energies in atoms, molecules and solids. I used these techniques to perform the first QMC calculation of the excitonic band structure of bulk silicon. I am currently using empirical pseudopotential techniques (EPM) and the Folded Spectrum Method (FSM) to calculate the electronic eigenstates of bulk crystals, superlattices and free standing and embedded semiconductor quantum dots. I am also interested in calculating the complicated strain profiles surrounding self-assembled quantum dots grown using the Stranski-Krastanow growth mode.  These strain fields alter the band offsets between quantum dots and the surrounding matrix material, which can dramatically alter the electronic structure of these systems.

Highlights:

• Excitonic band structure of bulk silicon
• Atomic structure and wavefunctions of a free-standing InAs quantum dot
• VRML image of the isosurface of electronic states in an InAs quantum dot, embedd in GaAs.

Publications: