Physics-Informed Deep Image Prior Reconstruction of In-Plane Magnetization from Scanning NV Magnetometry

TL;DR

This paper introduces a physics-informed deep image prior framework for reconstructing complex in-plane magnetization patterns from scanning NV magnetometry, improving accuracy without pre-trained datasets.

Contribution

It demonstrates a novel DIP-based method that effectively reconstructs nanoscale magnetization, incorporating spatial constraints and mask alignment for enhanced results.

Findings

Mask alignment improves reconstruction SNR by up to 3 dB.

The method requires no pre-trained datasets and is computationally efficient.

Reconstruction successfully captures Landau and dipole domain structures.

Abstract

Reconstructing magnetization in nanoscale magnetic thin films is essential for developing next-generation memory, sensors, and various spintronic technologies. However, this remains challenging due to the ill-posed nature of the stray field inverse problem, i.e., there are infinitely many magnetization solutions to a given stray field distribution. Here, we demonstrate that a physics-informed deep image prior (DIP) framework, using a simple convolutional autoencoder conditionally achieves a reasonable qualitative and quantitative reconstruction of complex in-plane magnetization patterns from scanning NV magnetometry. We find that the orientation of user-defined masks implemented to restrict the reconstruction solution space dramatically affects convergence. The optimal alignment of the mask improves the reconstruction signal-to-noise ratio by up to $\SI{3}{\decibel}$, thereby also serving as a diagnostic tool. The DIP approach requires no pre-trained datasets and is considered computationally less intensive as compared to supervised learning approaches. We analyze both Landau and dipole domain structures in lithographically patterned Permalloy nanostructures by incorporating experimentally-guided spatial constraints. Complementary magnetic force microscopy measurements were carried out to support the Scanning NV measurements.