Magnetic topological lithography: Gateway to the artificial spin ice manifold

TL;DR

This paper introduces magnetic topological lithography, a novel technique that enables full access to all microstates in artificial spin ice arrays, facilitating advanced control and exploration of complex magnetic states for technological applications.

Contribution

The paper presents a new surface-probe lithography method that allows complete microstate access in artificial spin ice, including previously unreachable states, advancing the study and utilization of frustrated magnetic systems.

Findings

Created the spin-crystal ground state of dipolar kagome ASI.

Generated high-energy monopole-chain states with negative effective temperatures.

Demonstrated control over microstates in nanomagnetic arrays.

Abstract

Nanomagnetic arrays are widespread in data storage and processing. As current technologies approach fundamental limits on size and thermal stability, extracting additional functionality from arrays is crucial to advancing technological progress. One design exploiting the enhanced magnetic interactions in dense arrays is the geometrically-frustrated metamaterial 'artificial spin ice' (ASI). Frustrated systems offer vast untapped potential arising from their unique microstate landscapes, presenting intriguing opportunities from reconfigurable logic to magnonic devices or hardware neural networks. However, progress in such systems is impeded by the inability to access more than a fraction of the total microstate space. Here, we present a powerful surface-probe lithography technique, magnetic topological lithography, providing access to all possible microstates in ASI and related nanomagnetic arrays. We demonstrate the creation of two previously elusive states; the spin-crystal ground state of dipolar kagome ASI and high-energy, low-entropy 'monopole-chain' states exhibiting negative effective temperatures.