Magnetic Hysteresis Experiments Performed on Quantum Annealers

TL;DR

This paper introduces a protocol for studying magnetic hysteresis on quantum annealers, demonstrating their potential for exploring non-equilibrium magnetic phenomena in condensed matter physics.

Contribution

It presents the first general method to measure magnetic hysteresis on programmable quantum annealers and applies it to various models and topologies.

Findings

Hysteresis loops depend non-monotonically on quantum fluctuations.

Disorder-induced steps and non-monotonicities observed in hysteresis.

Quantum annealers can probe emergent magnetic phenomena.

Abstract

While quantum annealers have emerged as versatile and controllable platforms for experimenting on correlated spin systems, the important phenomenology of magnetic memory and hysteresis remain unexplored on hardware designed to escape metastable states via quantum tunneling. Here, we present the first general protocol to experiment on magnetic hysteresis on programmable quantum annealers, and implement it on three D-Wave superconducting qubit quantum annealers, using up to thousands of spins, for both ferromagnetic and disordered Ising models, and across different graph topologies. We observe hysteresis loops whose area depends non-monotonically on quantum fluctuations, exhibiting both expected and unexpected features, such as disorder-induced steps and non-monotonicities. Our work establishes quantum annealers as a platform for probing non-equilibrium emergent magnetic phenomena, thereby broadening the role of analog quantum computers into foundational questions in condensed matter physics.