Large and tunable magnetoresistance in van der Waals ferromagnet/semiconductor junctions

Authors

Wenkai Zhu, Chinese Academy of Sciences, University of Chinese Academy of Sciences
Yingmei Zhu, Nanjing University
Tong Zhou, University at Buffalo
Xianpeng Zhang, University of Basel
Hailong Lin, Chinese Academy of Sciences, University of Chinese Academy of Sciences
Qirui Cui, Nanjing University
Faguang Yan, Chinese Academy of Sciences
Ziao Wang, Chinese Academy of Sciences, University of Chinese Academy of Sciences
Yongcheng Deng, Chinese Academy of Sciences
Hongxin Yang, Nanjing University
Lixia Zhao, Chinese Academy of Sciences, Tiangong University
Igor Žutić, University at Buffalo
Kirill D. Belashchenko, University of Nebraska-Lincoln
Kaiyou Wang, Chinese Academy of Sciences, University of Chinese Academy of Sciences, BeijingAcademy ofQuantumInformation Sciences

Date of this Version

9-4-2023

Citation

Nature Communications | ( 2023) 14:5371. https://doi.org/10.1038/s41467-023-41077-0

Comments

Open access.

Abstract

Magnetic tunnel junctions (MTJs) with conventional bulk ferromagnets separated by a nonmagnetic insulating layer are key building blocks in spintronics for magnetic sensors and memory. A radically different approach of using atomically-thin van der Waals (vdW) materials in MTJs is expected to boost their figure of merit, the tunneling magnetoresistance (TMR), while relaxing the lattice-matching requirements from the epitaxial growth and supporting high-quality integration of dissimilar materials with atomically-sharp interfaces. We report TMR up to 192% at 10 K in all-vdW Fe₃GeTe₂/GaSe/Fe₃GeTe₂ MTJs. Remarkably, instead of the usual insulating spacer, this large TMR is realized with a vdW semiconductor GaSe. Integration of semiconductors into the MTJs offers energy-band-tunability, bias dependence, magnetic proximity effects, and spin-dependent optical-selection rules. We demonstrate that not only the magnitude of the TMR is tuned by the semiconductor thickness but also the TMR sign can be reversed by varying the bias voltages, enabling modulation of highly spin-polarized carriers in vdW semiconductors.