Wide Field Imaging of van der Waals Ferromagnet Fe3GeTe2 by Spin Defects in Hexagonal Boron Nitride

TL;DR

This paper demonstrates nanoscale quantum imaging of ferromagnetism in Fe3GeTe2/hBN heterostructures using spin defects in hexagonal boron nitride, revealing local magnetic fluctuations and temperature-dependent magnetic behavior.

Contribution

It introduces a novel method for probing local magnetic properties in van der Waals heterostructures using spin defects in hBN, enabling precise quantum sensing of low-dimensional ferromagnetism.

Findings

Nanoscale imaging of ferromagnetism in Fe3GeTe2/hBN heterostructures.

Observation of magnetic fluctuations peaking near the Curie temperature.

Demonstration of spin relaxometry for local magnetic property measurement.

Abstract

Emergent color centers with accessible spins hosted by van der Waals materials have attracted substantial interest in recent years due to their significant potential for implementing transformative quantum sensing technologies. Hexagonal boron nitride (hBN) is naturally relevant in this context due to its remarkable ease of integration into devices consisting of low-dimensional materials. Taking advantage of boron vacancy spin defects in hBN, we report nanoscale quantum imaging of low-dimensional ferromagnetism sustained in Fe3GeTe2/hBN van der Waals heterostructures. Exploiting spin relaxometry methods, we have further observed spatially varying magnetic fluctuations in the exfoliated Fe3GeTe2 flake, whose magnitude reaches a peak value around the Curie temperature. Our results demonstrate the capability of spin defects in hBN of investigating local magnetic properties of layered materials in an accessible and precise way, which can be extended readily to a broad range of miniaturized van der Waals heterostructure systems.