Qubit spin ice

TL;DR

This paper demonstrates a quantum simulation of spin ice using superconducting qubits, revealing emergent phenomena like monopoles and Coulomb phases, and enabling control over quantum and thermal fluctuations in a disordered system.

Contribution

It introduces a novel realization of spin ice with superconducting qubits, incorporating quantum and thermal disorder, and demonstrates control over emergent monopoles and Coulomb phases.

Findings

Realization of spin ice in a superconducting qubit lattice.

Control over a degeneracy point leading to a Coulomb phase.

Demonstration of Gauss's law for emergent monopoles.

Abstract

Artificial spin ices are frustrated spin systems that can be engineered, wherein fine tuning of geometry and topology has allowed the design and characterization of exotic emergent phenomena at the constituent level. Here we report a realization of spin ice in a lattice of superconducting qubits. Unlike conventional artificial spin ice, our system is disordered by both quantum and thermal fluctuations. The ground state is classically described by the ice rule, and we achieve control over a fragile degeneracy point leading to a Coulomb phase. The ability to pin individual spins allows us to demonstrate Gauss's law for emergent effective monopoles in two dimensions. The demonstrated qubit control lays the groundwork for potential future study of topologically protected artificial quantum spin liquids.