Dimensional crossover of quantum critical dynamics in many-body phase transitions

The dimensional crossover induces varieties of quantum phenomena. In this paper, we demonstrate the quantum critical dynamics under dimensional crossover involving many-body phase transitions by continuously suppressing correlations and tunnelings along one direction of bulk materials, which provides a smooth connection from higher dimensions to lower ones based on the intrinsic correlations rather than geometry tailoring. By measuring the nonadiabatic excitations, the critical scaling laws in both three and two dimensions are observed and are consistent with predictions. In addition, we find scaling behaviors for intermediate regimes with noninteger dimensions. This study provides insights to extend the descriptions of critical exponents into more general or complex scenarios.