Condensed Matter Physics
A number of staff work in this area, including Professors Oleg Sushkov, Emeritus Professor Jaan Oitmaa, Visiting Professor David Neilson and Visiting Associate Professor Chris Hamer.
Professor Jaan Oitmaa and Associate Professor Chris Hamer study quantum lattice models in statistical mechanics, which may represent magnetic materials, high-temperature superconductors, or etc. Their aim is to study the critical behaviour of these systems near a phase transition, and to understand it in terms of an effective Lagrangian field theory. A particular topic of interest at the moment is ‘frustrated’ spin systems, offering the possibility of ‘spin-liquid’ states and ‘deconfined’ quantum critical points, where fractional excitations may appear in two-dimensional models. They would also like to understand how the phenomenon of high-temperature superconductivity arises. Numerical methods used include linked-cluster series expansions, density matrix renormalization group methods, exact diagonalization, and Quantum Monte Carlo simulations.
Alex Collins is a PhD student working on ‘triplet-wave’ and series expansion techniques for dimerized lattice spin models.