Speaker
Description
Quantum sensing and nanoscale magnetometry using the Nitrogen-Vacancy (NV) center in diamond has opened up a wide range of sensing possibilities. The NV center is an atomic-scale defect containing a single electron spin. A single NV center integrated into the tip of an all-diamond atomic force scanning probe enables high resolution, quantitative imaging of stray magnetic fields over a wide temperature range. Furthermore, the broad frequency range over which the NV center is sensitive enables imaging modalities to investigate nanoscale spin dynamics. Here, we use NV relaxometry and magnetic field imaging to probe static magnetizations and GHz spin dynamics in artificial kagome spin ice. The emergent correlations in artificial spin systems, consisting of arrays of lithographically fabricated mesoscale macrospins, have been studied extensively. However, the nanoscale relaxation behavior of the interacting magnetic islands has not yet been thoroughly probed experimentally. Due to the NV center’s non-invasive nature, we now have a tool to locally probe these nanoscale fluctuations in spin ice even in the superparamagnetic regime. We present spatial maps of static magnetization measured on a lattice of permalloy islands, which allow us to image the spin-ice arrangement and locally verify the validity of ice rules. We further provide relaxation images of spin dynamics, which indicate localized, increased fluctuations in the 3 GHz spectral band. These measurements provide insight into the nanoscale behavior of spins in physically rich spin ice systems and may ultimately allow us to locally probe collective spin ice excitations.
