Nature Communications (Sep 2023)

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

  • Wenkai Zhu,
  • Yingmei Zhu,
  • Tong Zhou,
  • Xianpeng Zhang,
  • Hailong Lin,
  • Qirui Cui,
  • Faguang Yan,
  • Ziao Wang,
  • Yongcheng Deng,
  • Hongxin Yang,
  • Lixia Zhao,
  • Igor Žutić,
  • Kirill D. Belashchenko,
  • Kaiyou Wang

DOI
https://doi.org/10.1038/s41467-023-41077-0
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 7

Abstract

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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.