Zheng Guolin, Xie Wen-Qiang, Albarakati Sultan, Algarni Meri, Tan Cheng, Wang Yihao, Peng Jingyang, Partridge James, Farrar Lawrence, Yi Jiabao, Xiong Yimin, Tian Mingliang, Zhao Yu-Jun, Wang Lan
School of Science, RMIT University, Melbourne VIC 3001, Australia.
Department of Physics, South China University of Technology, Guangzhou 510640, China.
Phys Rev Lett. 2020 Jul 24;125(4):047202. doi: 10.1103/PhysRevLett.125.047202.
The weak interlayer coupling in van der Waals (vdW) magnets has confined their application to two dimensional (2D) spintronic devices. Here, we demonstrate that the interlayer coupling in a vdW magnet Fe_{3}GeTe_{2} (FGT) can be largely modulated by a protonic gate. With the increase of the protons intercalated among vdW layers, interlayer magnetic coupling increases. Because of the existence of antiferromagnetic layers in FGT nanoflakes, the increasing interlayer magnetic coupling induces exchange bias in protonated FGT nanoflakes. Most strikingly, a rarely seen zero-field cooled (ZFC) exchange bias with very large values (maximally up to 1.2 kOe) has been observed when higher positive voltages (V_{g}≥4.36 V) are applied to the protonic gate, which clearly demonstrates that a strong interlayer coupling is realized by proton intercalation. Such strong interlayer coupling will enable a wider range of applications for vdW magnets.
范德华（vdW）磁体中的弱层间耦合限制了它们在二维（2D）自旋电子器件中的应用。在此，我们证明vdW磁体Fe₃GeTe₂（FGT）中的层间耦合可以通过质子门进行大幅调制。随着插入vdW层间的质子数量增加，层间磁耦合增强。由于FGT纳米片中存在反铁磁层，层间磁耦合的增强会在质子化的FGT纳米片中诱导交换偏置。最引人注目的是，当向质子门施加更高的正电压（V₉≥4.36 V）时，观察到了罕见的具有非常大值（最大可达1.2 kOe）的零场冷却（ZFC）交换偏置，这清楚地表明通过质子插入实现了强层间耦合。这种强层间耦合将使vdW磁体有更广泛的应用。
