Gigantic Current Control of Coercive Field and Magnetic Memory Based on Nanometer-Thin Ferromagnetic van der Waals Fe3 GeTe2

Kaixuan Zhang; Seungyun Han; Youjin Lee; Matthew J Coak; Junghyun Kim; Inho Hwang; Suhan Son; Jeacheol Shin; Mijin Lim; Daegeun Jo; Kyoo Kim; Dohun Kim; Hyun-Woo Lee; Je-Geun Park

doi:10.1002/adma.202004110

Gigantic Current Control of Coercive Field and Magnetic Memory Based on Nanometer-Thin Ferromagnetic van der Waals Fe₃ GeTe₂

Adv Mater. 2021 Jan;33(4):e2004110. doi: 10.1002/adma.202004110. Epub 2020 Dec 6.

Authors

Kaixuan Zhang^{1

2

3}, Seungyun Han⁴, Youjin Lee^{1

2

3}, Matthew J Coak^{1

2}, Junghyun Kim^{1

2

3}, Inho Hwang^{1

2

3}, Suhan Son^{1

2

3}, Jeacheol Shin², Mijin Lim⁴, Daegeun Jo⁴, Kyoo Kim⁵, Dohun Kim², Hyun-Woo Lee^{4

6}, Je-Geun Park^{1

2

3}

Affiliations

¹ Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea.
² Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea.
³ Center for Quantum Materials, Seoul National University, Seoul, 08826, South Korea.
⁴ Department of Physics, Pohang University of Science and Technology, Pohang, 37673, South Korea.
⁵ Korea Atomic Energy Research Institute, 111 Daedeok-daero, Daejeon, 34057, South Korea.
⁶ Asia Pacific Center for Theoretical Physics, 77 Cheongam-ro, Nam-gu, Pohang, 3773, South Korea.

PMID: 33283320
DOI: 10.1002/adma.202004110

Abstract

Controlling magnetic states by a small current is essential for the next-generation of energy-efficient spintronic devices. However, it invariably requires considerable energy to change a magnetic ground state of intrinsically quantum nature governed by fundamental Hamiltonian, once stabilized below a phase-transition temperature. Here, it is reported that, surprisingly, an in-plane current can tune the magnetic state of the nanometer-thin van der Waals ferromagnet Fe₃ GeTe₂ from a hard magnetic state to a soft magnetic state. It is a direct demonstration of the current-induced substantial reduction of the coercive field. This surprising finding is possible because the in-plane current produces a highly unusual type of gigantic spin-orbit torque for Fe₃ GeTe₂ . In addition, a working model of a new nonvolatile magnetic memory based on the principle of the discovery in Fe₃ GeTe₂ , controlled by a tiny current, is further demonstrated. The findings open up a new window of exciting opportunities for magnetic van der Waals materials with potentially huge impact on the future development of spintronic and magnetic memory.

Keywords: 2D topological ferromagnetic metal Fe3GeTe2; current-tunable coercive field; magnetic van der Waals materials; spintronic and magnetic memory; unusually large spin-orbit torque.

Abstract

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