Anti-Kibble-Zurek Behavior in Crossing the Quantum Critical Point of a Thermally Isolated System Driven by a Noisy Control Field

TL;DR

This paper demonstrates that in a thermally isolated quantum system driven across a critical point with noisy control, slower driving can increase excitations, revealing limitations of adiabatic methods like quantum annealing.

Contribution

It uncovers anti-Kibble-Zurek behavior caused by noise, showing that slower ramps can be detrimental and identifying universal scaling laws for optimal driving.

Findings

Slower driving increases excitations in noisy quantum systems.

Optimal ramping time scales as a power law with noise strength.

Universal behavior of the optimal ramping rate is demonstrated.

Abstract

We show that a thermally isolated system driven across a quantum phase transition by a noisy control field exhibits anti-Kibble-Zurek behavior, whereby slower driving results in higher excitations. We characterize the density of excitations as a function of the ramping rate and the noise strength. The optimal driving time to minimize excitations is shown to scale as a universal power law of the noise strength. Our findings reveal the limitations of adiabatic protocols such as quantum annealing and demonstrate the universality of the optimal ramping rate.