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

• Published in: Science (American Association for the Advancement of Science) Vol. 360; no. 6394
• Main Authors: Klein, D. R., MacNeill, D., Lado, J. L., Soriano, D., Navarro-Moratalla, E., Watanabe, K., Taniguchi, T., Manni, S., Canfield, P., Fernandez-Rossier, J., Jarillo-Herrero, P.
• Format: Journal Article
• Language: English
• Published: United States AAAS 03.05.2018
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aar3617

Magnetic insulators are a key resource for next-generation spintronic and topological devices. The family of layered metal halides promises varied magnetic states, including ultrathin insulating multiferroics, spin liquids, and ferromagnets, but device-oriented characterization methods are needed to unlock their potential. In this paper, 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 interlayer 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. Finally, we further measure inelastic tunneling spectra for our junctions, unveiling a rich spectrum consistent with collective magnetic excitations (magnons) in CrI3.