Topological and nontopological defects from quantum reset dynamics

We analyze mechanisms for universal out-of-equilibrium dynamics near criticality by exploring the effect of randomized quantum resetting (QR) under a linear finite-time drive across, or very close to, an equilibrium quantum critical point. Using the transverse-field Ising chain as a minimal model and exploiting its exact solution, QR is found to cause a crossover of the scaling of the defect density with the time scale τ of the drive, from Kibble-Zurek to anti-Kibble-Zurek scaling as τ increases. Depending on whether the ramp ends in a symmetry-broken phase or not, the resulting defects are topological or nontopological. The competition between QR and the Kibble-Zurek mechanism gives rise to local minima of the defect densities at optimal annealing times. These times and the corresponding local minima are shown to scale as universal power laws with the rate of QR. Additional results for the scaling of the mean excess energy suggest that a system driven across, or very close to, a quantum critical point exhibits the same scaling behavior under a linear finite-time drive with QR as with uncorrelated noise. We suggest that these results may serve as benchmarks for validating quantum annealing devices.