Scanning gradiometry with a single spin quantum magnetometer

Abstract

Here, we demonstrate a gradiometry technique that significantly enhances the measurement sensitivity of such static fields, leading to new opportunities in the imaging of weakly magnetic systems. Our method relies on the mechanical oscillation of a single nitrogen-vacancy center at the tip of a scanning diamond probe, which up-converts the local spatial gradients into ac magnetic fields enabling the use of sensitive ac quantum protocols. We show that gradiometry provides important advantages over static field imaging: (i) an order-of-magnitude better sensitivity, (ii) a more localized and sharper image, and (iii) a strong suppression of field drifts. We demonstrate the capabilities of gradiometry by imaging the nanotesla fields appearing above topographic defects and atomic steps in an antiferromagnet, direct currents in a graphene device, and para- and diamagnetic metals.

11 pages, 5 figures

References in corpus (24)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Robust isothermal electric switching of interface magnetization: A route to voltage-controlled spintronics
• Scanning magnetic field microscope with a diamond single-spin sensor
• Probing magnetism in 2D materials at the nanoscale with single spin microscopy
• Extending Quantum Coherence in Diamond
• Resolved sidebands in a strain-coupled hybrid spin-oscillator system
• Real-space imaging of non-collinear antiferromagnetic order with a single spin magnetometer
• The nature of domain walls in ultrathin ferromagnets revealed by scanning nanomagnetometry
• Single-spin magnetometry with multi-pulse sensing sequences
• Imaging phonon-mediated hydrodynamic flow in WTe2
• Nanoscale electric-field imaging based on a quantum sensor and its charge-state control under ambient condition
• Magnetic domains and domain wall pinning in two-dimensional ferromagnets revealed by nanoscale imaging
• Nanoscale mechanics of antiferromagnetic domain walls
• Coherent, mechanical control of a single electronic spin
• Current-driven dynamics and ratchet effect of skyrmion bubbles in a ferrimagnetic insulator
• Spin-like susceptibility of metallic and insulating thin films at low temperature
• Co-existence of Bloch and Neel walls in a collinear antiferromagnet
• Characterization of room-temperature in-plane magnetization in thin flakes of CrTe${}_2$ with a single spin magnetometer
• Nanoscale vector electric field imaging using a single electron spin
• Magnetic, thermal, and topographic imaging with a nanometer-scale SQUID-on-cantilever scanning probe
• Imaging of sub-$\mu$A currents in bilayer graphene using a scanning diamond magnetometer
• Room-temperature detection of single 20 nm super-paramagnetic nanoparticles with an imaging magnetometer
• Scanning SQUID microscopy in a cryogen-free dilution refrigerator
• Scanning optical homodyne detection of high-frequency picoscale resonances in cantilever and tuning fork sensors

Cited by in corpus (4)

• Nanoscale Electric Field Imaging with an Ambient Scanning Quantum Sensor Microscope
• Strong manipulation of the valley splitting upon twisting and gating in MoSe${}_2$/CrI${}_3$ and WSe${}_2$/CrI${}_3$ van der Waals heterostructures
• Imaging ferroelectric domains with a single-spin scanning quantum sensor
• Crossed Andreev reflection in spin-polarized chiral edge states due to the Meissner effect