Continuous phase transition of a fully frustrated XY model in three dimensions

We have used Monte Carlo simulations, combined with finite-size scaling and two different real-space renormalization group approaches, to study a fully frustrated three-dimensional XY model on a simple cubic lattice. This model corresponds to a lattice of Josephson-coupled superconducting grains in an applied magnetic field H=(Φ_0/a^2)(1/2,1/2,1/2). We find that the model has a continuous phase transition with critical temperature T_c=0.681 J/kB, where J is the XY coupling constant, and critical exponents α/ν=0.87±0.01, v/ν=0.82±0.01, and ν=0.72±0.07, where α, v, and ν describe the critical behavior of the specific heat, helicity modulus, and correlation length. We briefly compare our results with other studies of this model, and with a mean-field approximation