Computational materials physics group

Research

At the most fundamental level, first-principles quantum mechanical methods are remarkably successful in describing the structure and electronic and vibrational excitations that determine the properties of materials. Most calculations of electronic properties are done using density functional theory (DFT) with the local-density approximaion (LDA), a very successful method for approximately reducing the full many-electron problem to an effective one-particle Schrodinger's equation. The DFT approximations break down in materials with strong electron-electron interactions, such as the high-temperature superconductors. Quantum Monte Carlo (QMC) methods must be used to study these systems. QMC methods allow essentially exact calculations of ground-state and finite-temperature equilibrium properties of interacting many electron systems. Recent research topics include:

• Development of computational methods and high-performance computing with applications to tackle significant physical problems
• Auxilliary-field QMC method for real materials (reprint)
• Ferroelectrics and piezoelectric materials. We are participants in a multi-institutional effort to develop better piezoelectrics at the Center for Piezoelectrics by Design (CPD)
• Superfluid-insulator phase transitions in dirty boson
• Quantum spin systems
• Critical behavior of equilibrium crystal shapes
• Properties of liquid helium droplets
• High-temperature superconductivity