Periodic Reporting for period 2 - EXAFONIS (Exploring antiferromagnetic order at the nanoscale with a single spin microscope)
Période du rapport: 2022-03-01 au 2023-08-31
In this context, the project EXAFONIS proposes to exploit the unique performances offered by a new generation of quantum magnetometers based on a single Nitrogen-Vacancy (NV) defect in diamond to investigate the AF order at the nanoscale. Two main objectives are pursued. The first objective is to provide a deep understanding of the microscopic mechanisms at the origin of AF manipulation by external stimuli, such as strain, electric fields or spin-polarized currents. The second objective is to demonstrate the detection and manipulation of magnetic skyrmions in AF materials, thus integrating topology in the vibrant area of AF spintronics.
Besides the study of BFO, we have also shown that non-collinear AF spin textures can be imaged with nanoscale spatial resolution by probing the magnetic noise they locally produce via thermal populations of magnons. This was achieved by adding a relaxometry-based imaging mode to the scanning-NV magnetometry toolbox, which relies on measurements of variations in the photoluminescence signal of the NV defect induced by magnetic noise. As a proof-of-concept, the efficiency of this novel method was first demonstrated by imaging domain walls and spin spirals in synthetic antiferromagnets (SAF). We then showed that NV-based relaxometry enables to image isolated skyrmions in SAF, which was an important goal of EXAFONIS.