Dynamics of a 2D disordered dipolar interacting spin ensemble on the surface of diamond

Statistical mechanics has long been the framework which connects the microscopic world to macroscopic observables. However, its fundamental assumption has been shown to break down in a class of strongly disordered systems, resulting in a slowdown or absence of thermalization. In this work, we use a shallow nitrogen-vacancy center to probe the dynamics of disordered dipolar interacting electronic spin-1/2 defects on the diamond surface. Using magnetic resonance techniques, we characterize and control the strength of disorder and dipolar interactions among the electronic spins. We measure the autocorrelation of individual spin projection, which exhibits a decay on a time scale much slower than the inverse interaction strength, indicating a substantial slowdown of thermalization.