Probing magnetism in 2D van der Waals crystalline insulators via electron tunneling

TLDR: In this paper, the authors report tunneling through the layered magnetic insulator CrI3 as a function of temperature and applied magnetic field and electrically detect the magnetic ground state and interlayer coupling and observe a field-induced metamagnetic transition.

Abstract: Magnetic insulators are a key resource for next-generation spintronic and topological devices The family of layered metal halides promises ultrathin insulating multiferroics, spin liquids, and ferromagnets, but new characterization methods are required to unlock their potential Here, we report tunneling through the layered magnetic insulator CrI3 as a function of temperature and applied magnetic field We electrically detect the magnetic ground state and inter-layer coupling and observe a field-induced metamagnetic transition The metamagnetic transition results in magnetoresistances of 95%, 300%, and 550% for bilayer, trilayer, and tetralayer CrI3 barriers, respectively We further measure inelastic tunneling spectra for our junctions, unveiling a rich spectrum of collective magnetic excitations (magnons) in CrI3 Our results establish vertical tunneling as a versatile probe of magnetism in atomically thin insulators