English

Time-averaged quantum annealing for weak processes

Quantum Physics 2023-06-18 v1 Statistical Mechanics

Abstract

The quantum Ising chain has shortcuts to adiabaticity when operated with weak processes. However, when exactly do the non-equilibrium effects of the Kibble-Zurek mechanism, inherent to the system, appear in the optimal protocols in such a context? I propose here that such contrasting difference occurs due to the manner by which one measures the excitation spent energy of the system. Therefore, in this work, I made a qualitative analysis of a quantum annealing procedure of the time-averaged excess work, where the system acquires as a diverging decorrelation time the heuristic Kibble-Zurek mechanism relaxation time. Four important effects are then observed: the absence of shortcuts to adiabaticity, the pausing effect around the critical point in the optimal protocol when the Kibble-Zurek mechanism holds, the persistence of the time-averaged work to avoid slowly-varying regime even for large switching times, and diverging fluctuations of the time-averaged work. In the end, by comparing the excess and the time-averaged excess works, I conclude that this last one is not useful to measure the excitation spent energy in weak processes, although brings an intuition to what happens in the strong driving case.

Keywords

Cite

@article{arxiv.2306.06008,
  title  = {Time-averaged quantum annealing for weak processes},
  author = {Pierre Nazé},
  journal= {arXiv preprint arXiv:2306.06008},
  year   = {2023}
}

Comments

6 pages, 2 figures. arXiv admin note: text overlap with arXiv:2303.15609, arXiv:2305.17802, arXiv:2210.16116

R2 v1 2026-06-28T11:01:12.200Z