Quantum critical behaviour of a disordered granular superconductor with charging effects

The effect of quantum fluctuations of the phase on the low-temperature critical behaviour of a three-dimensional disordered (site-diluted) granular superconductor with Coulomb interactions is studied using the renormalization group method. In the one-loop approximation the system exhibits a focus-type stable fixed point which gives rise to unusual critical behaviour with oscillating corrections to the scaling.