Professor Arun Paramekanti

University of Toronto

A staggered current Mott insulator of kinetically frustrated bosons

Abstract:

Various recent experiments on ultracold atoms have begun to explore the physics of frustrated bosons. Motivated by these developments, I will discuss the Hubbard model of bosons, in the presence of fluxes which lead to kinetic frustration. This model is also the simplest quantum variant of the well studied fully frustrated Josephson junction array. While weak repulsive interactions in this model lead to unconventional superfluidity, the effect of strong correlations is less well understood. I will show using various approaches that between this superfluid and the conventional Mott insulator lies an unusual Mott insulator which supports staggered loop currents that spontaneously break time reversal symmetry. This provides a very simple bosonic analogue of staggered current electronic states proposed in the context of cuprate superconductivity.