Nanoscale Vector Magnetic Sensing with Current‐Driven Stochastic Nanomagnet

Abstract

Detection of vector magnetic fields at nanoscale dimensions is critical in applications ranging from basic material science and fundamental physics to information storage and medical diagnostics. So far, nanoscale vector magnetic field sensing is achieved solely by exploiting a single nitrogen‐vacancy (NV) center in a diamond, by evaluating the Zeeman splitting of NV spin qubits by using the technique of an optically‐detected magnetic resonance. This protocol requires a complex optical setup and expensive detection systems to detect the photoluminescence light, which may limit miniaturization and scalability. Here, a simple approach with all‐electric operation to sensing a vector magnetic field at 200 × 200 nm2 dimensions is experimentally demonstrated, by monitoring a stochastic nanomagnet's transition probability from a metastable state, excited by a driving current due to spin‐orbit torque, to a settled state.

Wide Linearity Range 3D Magnetic Sensor and Angular Position Detector Based on a Single FePt Spin–Orbit Torque Device

“…This enables the utilization of the linear response characteristics of the domains' random switching probability to detect magnetic fields. 26 Furthermore, we measured the Hall resistance R xy as a function of the rotating field angle θ yz based on the 15 μm device. The specification of x−y−z coordinates is shown in Figure 5a, along with the design of a 3D sensor mounted in a vector magnetic field.…”

“…Considering it is a nanowire structure, if we further reduce the device size and create a nanodot structure, the device can be transformed into a single-domain structure. This enables the utilization of the linear response characteristics of the domains’ random switching probability to detect magnetic fields …”