Visualizing Field-free Deterministic Magnetic Switching of all-van der Waals Spin-Orbit Torque System Using Spin Ensembles in Hexagonal Boron Nitride

TL;DR

This paper demonstrates a novel quantum imaging technique using van der Waals spin defects to visualize and analyze field-free deterministic magnetic switching in a 2D vdW magnet at room temperature, revealing complex spin interactions.

Contribution

It introduces a new quantum imaging approach with hexagonal boron nitride to visualize magnetic switching in 2D vdW systems, providing insights into spin dynamics and device design.

Findings

Visualization of SOT-driven magnetic stray field variations

Revealed transition from deterministic to indeterministic switching

Insights into spin interactions and effects of Joule heating

Abstract

Recently, optically active spin defects embedded in van der Waals (vdW) crystals have emerged as a transformative quantum sensing platform to explore cutting-edge materials science and quantum physics. Taking advantage of excellent solid-state integrability, this new class of spin defects can be arranged in controllable nanoscale proximity of target materials in vdW heterostructures, showing great promise for improving spatial resolution and field sensitivity of current sensing technologies. Building on this state-of-the-art measurement platform, here we report hexagonal boron nitride-based quantum imaging of field-free deterministic magnetic switching of room-temperature two-dimensional magnet Fe3GaTe2 in an all-vdW spin-orbit torque (SOT) system. By visualizing SOT-driven variations of nanoscale Fe3GaTe2 magnetic stray field profile under different conditions, we have revealed how the observed magnetic switching evolves from deterministic to indeterministic behavior due to the interplay between out-of-plane spins, in-plane spins and Joule heating. This understanding, which is otherwise difficult to access by conventional transport measurements, offers valuable insights on material design, testing, and evaluation of next-generation vdW spintronic devices.