Min Keun-Hong, Lee Duk Hyun, Choi Sang-Jun, Lee In-Ho, Seo Junho, Kim Dong Wook, Ko Kyung-Tae, Watanabe Kenji, Taniguchi Takashi, Ha Dong Han, Kim Changyoung, Shim Ji Hoon, Eom Jonghwa, Kim Jun Sung, Jung Suyong
Interdisciplinary Materials Measurement Institute, Korea Research Institute of Standards and Science, Daejeon, Republic of Korea.
Department of Physics and Astronomy, Sejong University, Seoul, Republic of Korea.
Nat Mater. 2022 Oct;21(10):1144-1149. doi: 10.1038/s41563-022-01320-3. Epub 2022 Aug 4.
Van der Waals heterostructures with two-dimensional magnets offer a magnetic junction with an atomically sharp and clean interface. This attribute ensures that the magnetic layers maintain their intrinsic spin-polarized electronic states and spin-flipping scattering processes at a minimum level, a trait that can expand spintronic device functionalities. Here, using a van der Waals assembly of ferromagnetic FeGeTe with non-magnetic hexagonal boron nitride and WSe layers, we demonstrate electrically tunable, highly transparent spin injection and detection across the van der Waals interfaces. By varying an electrical bias, the net spin polarization of the injected carriers can be modulated and reversed in polarity, which leads to sign changes of the tunnelling magnetoresistance. We attribute the spin polarization reversals to sizable contributions from high-energy localized spin states in the metallic ferromagnet, so far inaccessible in conventional magnetic junctions. Such tunability of the spin-valve operations opens a promising route for the electronic control of next-generation low-dimensional spintronic device applications.
具有二维磁体的范德华异质结构提供了一个具有原子级锐利且清洁界面的磁结。这一特性确保了磁性层保持其固有的自旋极化电子态，并将自旋翻转散射过程降至最低水平，这一特性可以扩展自旋电子器件的功能。在此，我们利用铁磁体FeGeTe与非磁性六方氮化硼和WSe层的范德华组装，展示了跨范德华界面的电可调、高透明自旋注入和检测。通过改变电偏压，可以调制注入载流子的净自旋极化并反转其极性，这导致隧穿磁电阻的符号变化。我们将自旋极化反转归因于金属铁磁体中高能局域自旋态的显著贡献，这在传统磁结中迄今无法实现。这种自旋阀操作的可调性为下一代低维自旋电子器件应用的电子控制开辟了一条有前景的途径。
