Phase diagram of the spin1/2 Heisenberg antiferromagnet an an inhomogeneously bonddiluted square lattice, consisting of ladders connected by dimers. P_L is the ladder bond activation probability, and P_D is the activation probability for dimer bonds. The bond strengths are chosen to be equal.

   Our group is interested in topics related to quantum magnetism, superconductivity, and nanotechnology. We investigate microscopic models of interacting electronic systems, and use numerical techniques, such as Quantum Monte Carlo and Exact Diagonalization, to find their phase diagrams, ground state properties, and excitation spectra. Recently, we have applied the Stochastic Series Expansion Method to study field induced phase transitions in quantum spin liquids, developed optimization algorithms to construct nanoscale optoelectronic devices, and applied BCS theory to investigate the consequences of unconventional superconductivity in strongly correlated materials. Our work is motivated by and connected to recent experiments in the fields of quantum antiferromagnetism, hightemperature and heavyfermion superconductivity, and nanophotonics.
 
