Shumway Research Group

Department of PhysicsArizona State UniversityTempe • AZ
Research in Path Integral Simulations, Quantum States of Matter, and Nanoscale Electronics

Quantum Dot Physics

When electrons are confined to small spaces, they no longer apear to be pointlike particles, but instead behave as waves. Some well-known examples of electron wavefunctions are the atomic and molecular orbitals of physical chemistry. These wavefunctions are quantum states, whose behavior is described by the equations of quantum mechanics, such as Schödinger's equation or Feynman path integrals. Recent advances in nanotechnology have given scientists the ability to fabricate, manipulate, image, and measure structures a few nanometers across. These nanostructures are composed of tens to thousands of atoms, and are able to confine electrons in quantum states. The simplest of these structures confine electrons in small spherical or circular spaces, and are known as quantum dots.




A major component of our research program is the development of computer algorithms for solving the equations of quantum physics. These computer simulations generate quantitative information about the dots and other quantum devices. Simulation data aids in design and interpretation of experiments, and form a link between general ideas of theoretical physics and detailed measurements of specific experiments. Our specialty is the use of stochastic algorithms, known as Quantum Monte Carlo (QMC).

Reproducibility of calculations is important to scientific integrity and progress in computational physics. We are releasing source code for some of our quantum dot simulations in an effort to cooperate with other research groups and aid begining researchers. These nanostructure modeling codes are being distributed under the GNU GPL for open source software.