
Theory of Strongly Correlated Systems 
There are a number of interesting phenomena in condensed matter physics. We are particularly interested in remarkable properties of strongly correlated systems. In addition to standard techniques such as perturbation expansion and meanfield theory, we use numerical powerful techniques such as exact diagonalization, quantum Monte Carlo simulations and numerical renormalization group to clarify how particle correlations affect a wide variety of quantum systems at low temperatures.
Our recent interests:

 Optical lattice system 
 Strongly correlated electron systems on quasiperiodic lattice 
 Strongly correlated electron systems with orbital degeneracy 
 Quantum spin systems with geometrical frustration 
