Path-Integral Quantum Monte Carlo Techniques for Self-Assembled Quantum Dots

We have developed a set of path integral quantum Monte Carlo techniques for studying self-assembled quantum dots. The simulations can be run in two or three dimensions, with a variety of different effective mass models. Our most realistic simulations start from an atomistic model of dot shape, size, and composition, then compute strain-modified band offsets to use as input for the path integral algorithms. We have studied charge distributions and total energies for different numbers of electrons and holes in a variety of InGaAs/GaAs quantum dots. New techniques allow us to apply external electronic and magnetic fields. We have also gone beyond the parabolic band approximation by including an energy-dependent effective mass (in mathematical analogy to relativistic kinetic energy). Finally, we describe a path-integral method for calculating the degree to which biexcitonic correlation suppresses radiative recombination rates.