Chirality of triangular antiferromagnetic clusters as a qubit

TL;DR

This paper proposes using the chirality of triangular antiferromagnetic clusters as a qubit, enabling quantum information processing with potential for direct measurement and implementation in molecular magnets or surface-placed Cu atoms.

Contribution

It introduces a novel qubit encoding based on chirality, independent of total spin, and details methods for measurement, gate operations, and discusses decoherence effects.

Findings

Chirality can serve as a robust qubit degree of freedom.

Orbital moments allow direct chirality measurement with magnetic fields.

Feasible implementations with molecular magnets and Cu atom surfaces.

Abstract

We show that the chirality of triangular antiferromagnetic clusters can be used as a qubit even if it is entirely decoupled from the total spin of the cluster. In particular, we estimate the orbital moment associated to the chirality, and we show that it can be large enough to allow a direct measurement of the chirality with a field perpendicular to the cluster. Consequences for molecular magnets are discussed, and an alternative implementation with Cu atoms on a surface is proposed, for which one- and two-qubit gates are worked out in detail. Decoherence effects are also discussed.