Topological Defects from Quantum Reset Dynamics

Abstract

We analyze mechanisms for universal out-of-equilibrium dynamics near criticality by exploring the effect of randomized quantum resetting (QR) under a finite-time quench across a quantum phase transition. Using the transverse-field Ising chain as a generic model and exploiting its exact solution, QR is found to cause a crossover of the scaling of the topological defect density with the time scale $\ddot{I}„$ of the quench, from Kibble-Zurek to anti-Kibble-Zurek scaling as $\ddot{I}„$ increases. This reflects a competition between non-adiabatic quench-driven excitations and QR, giving 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 a quantum critical point exhibits the same scaling behavior under a linear quench with QR as with uncorrelated noise.

6 pages with 3 figures. More information and the latest version can be found at https://www.physik.uni-kl.de/eggert/papers/