Harnessing Chiral Spin States in Molecular Nanomagnets for Quantum Technologies

TL;DR

This paper develops a theoretical framework for creating chiral qubits in molecular nanomagnets, leveraging spin chirality to suppress unwanted interactions, with validation on lanthanide complexes, advancing molecular quantum technology.

Contribution

Introduces a novel theoretical approach to engineer spin chirality in molecular systems for quantum computing, addressing always-on interaction issues in weakly coupled qubits.

Findings

Chiral ground states characterized by nonzero scalar spin chirality.

Chiral qubits suppress always-on interactions effectively.

Validation on lanthanide complexes shows practical feasibility.

Abstract

We present a theoretical framework to investigate spin chirality in molecular quantum systems. Focusing on a minimal three-spin-center model with antiferromagnetic exchange and symmetry breaking driven by an electric-field-induced Dzyaloshinskii-Moriya interaction and applied magnetic fields-give rise to chiral ground states characterized by nonzero scalar spin chirality, $\chi = \textbf{S}_1\cdot(\textbf{S}_r\times \textbf{S}_2)$. The emergent chiral qubits naturally suppress always-on interactions that can not be switched off in weakly coupled qubits, as demonstrated through Liouville-von Neumann dynamics, which reveal phase difference in superposition states that form chiral qubits. To validate this framework, we examine realistic lanthanide complexes with radical-bridged magnetic centers, where spin-orbit coupling and asymmetric exchange facilitate chirality. Our findings establish spin chirality engineering as a promising strategy for mitigating always-on interaction in entangling two chiral qubits in molecular quantum technologies.