Fractonic criticality in Rydberg atom arrays

Fractonic matter can undergo unconventional phase transitions driven by the condensation of particles that move along subdimensional manifolds. We propose that this type of quantum critical point can be realized in a bilayer of crossed Rydberg chains. This system exhibits a transition between a disordered phase and a charge-density-wave phase with subextensive ground state degeneracy. The transition is described by a stack of critical Ising conformal field theories that become decoupled in the low-energy limit due to emergent subsystem symmetries. We discuss the unusual scaling properties and derive anisotropic correlators that provide signatures of subdimensional criticality in a realistic setup.