Southwestern Ontario 4-Corner Condensed Matter Symposium - 2008

I will discuss the interplay between the fermionic nodal quasiparticles of a d-wave superconductor and the various spin and charge orders that have been observed in the cuprate superconductors. Fluctuations of a composite \'nematic\' order are identified as the dominant source of inelastic…

URu2Si2 is a moderate heavy fermion system which undergoes two transitions with decreasing temperature. The lower transition (1.5K) is to a possibly unconventional superconducting state, whereas the nature of the upper transition (17.5K) is poorly understood. Large lambda-like anomalies are seen in…

I present a short review of recent developments both in experiment and theory in Quantum Hall Effect in Graphene. The emphasis is on the interpretation of the dynamics underlying recently experimentally discovered novel plateaus in strong magnetic fields (B > 20 T).

Motivated by recent observations of superfluidity of ultracold fermions in optical lattices, we investigate the stability of superfluid flow of paired fermions in the lowest band of a strong optical lattice. For fillings close to one fermion per site, we show that superflow breaks down via a…

Responding electrically to magnetic stimuli and vise versa, multiferroics offer exciting possibilities for applications and challenge our understanding of coupled lattice and spin degrees of freedom in solids. I discuss how multiferroic properties can develop in frustrated magnets where competing…

Calculating universal properties of quantum phase transitions in microscopic Hamiltonians is a challenging task, made possible through large-scale numerical simulations coupled with finite-size scaling analyses. The continuing advancement of quantum Monte Carlo technologies, together with modern…

There are a few examples in the literature of metals that, in the T  0 K limit, show a resistivity that rises with decreasing temperature without any sign of either saturation or a gap. Well known cases include underdoped cuprates in high magnetic fields and some doped uranium heavy fermion…

Based on a U(1) gauge theory of the Hubbard model on the triangular lattice, it is argued that a spin liquid phase may exist near the Mott transition in the organic compound κ-(BEDT-TTF)2Cu2(CN)3. In the spin liquid state, low energy excitations are fermionic spinons and an emergent U(1) gauge boson…