Continuous-time Monte Carlo renormalization group

We implement the Monte Carlo renormalization group approach in the continuous-time Monte Carlo simulation of a quantum system. We demonstrate numerically the emergent isotropy between space and time at large distances for the systems that exhibit Lorentz invariance at quantum criticality. This allows us to estimate accurately the sound velocity for these quantum systems. Q-state Potts models in one and two space dimensions are used to illustrate the method.