Multi-Angle Reconstruction of Domain Morphology with All-Optical Diamond Magnetometry

TL;DR

This paper introduces a multi-angle reconstruction method (MARe) for diamond magnetometry that enables nanoscale imaging of magnetic domain morphology across all magnetic-field regimes, including high-field conditions where optical signals are quenched.

Contribution

The paper presents a novel MARe technique that extends the capabilities of NV-based magnetometry to high magnetic fields, allowing comprehensive surface magnetisation imaging.

Findings

Successfully imaged magnetic domains in multilayer films with high surface magnetisation.

Demonstrated the method's effectiveness in regimes where optical signals are quenched.

Extended the applicability of NV magnetometry to a broader range of magnetic materials.

Abstract

Scanning diamond magnetometers based on the optically detected magnetic resonance of the nitrogen-vacancy centre offer very high sensitivity and non-invasive imaging capabilities when the stray fields emanating from ultrathin magnetic materials are sufficiently low (< 10 mT). Beyond this low-field regime, the optical signal quenches and a quantitative measurement is challenging. While the field-dependent NV photoluminescence can still provide qualitative information on magnetic morphology, this operation regime remains unexplored particularly for surface magnetisation larger than $\sim$ 3 mA. Here, we introduce a multi-angle reconstruction technique (MARe) that captures the full nanoscale domain morphology in all magnetic-field regimes leading to NV photoluminescence quench. To demonstrate this, we use [Ir/Co/Pt]$_{14}$ multilayer films with surface magnetisation an order of magnitude larger than previous reports. Our approach brings non-invasive nanoscale magnetic field imaging capability to the study of a wider pool of magnetic materials and phenomena.