Kagome qubit ice

TL;DR

This paper demonstrates a field-induced kinetic crossover between spin-liquid phases in kagome spin ice realized with superconducting qubits, revealing new topological phases and fractionalized excitations using quantum annealing.

Contribution

It introduces a novel experimental realization of kagome spin ice in a quantum annealer and observes distinct kinetic regimes and topological phases through controlled magnetic fields.

Findings

Evidence of Ice-I and Ice-II phases in kagome spin ice.

Observation of a kinetic crossover between different spin-liquid phases.

Detection of fractionalized excitations via quantum annealing.

Abstract

Topological phases of spin liquids with constrained disorder can host a kinetics of fractionalized excitations. However, spin-liquid phases with distinct kinetic regimes have proven difficult to observe experimentally. Here we present a realization of kagome spin ice in the superconducting qubits of a quantum annealer, and use it to demonstrate a field-induced kinetic crossover between spin-liquid phases. Employing fine control over local magnetic fields, we show evidence of both the Ice-I phase and an unconventional field-induced Ice-II phase. In the latter, a charge-ordered yet spin-disordered topological phase, the kinetics proceeds via pair creation and annihilation of strongly correlated, charge conserving, fractionalized excitations. As these kinetic regimes have resisted characterization in other artificial spin ice realizations, our results demonstrate the utility of quantum-driven kinetics in advancing the study of topological phases of spin liquids.