Tsai Hanshen, Higo Tomoya, Kondou Kouta, Sakamoto Shoya, Kobayashi Ayuko, Matsuo Takumi, Miwa Shinji, Otani Yoshichika, Nakatsuji Satoru
Institute for Solid State Physics University of Tokyo Kashiwa Chiba 277-8581 Japan.
CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan.
Small Sci. 2021 Apr 15;1(5):2000025. doi: 10.1002/smsc.202000025. eCollection 2021 May.
Developing a technology to electrically manipulate a Weyl semimetal state is a vital step for designing a nonvolatile memory using topologically robust properties. Recently, such manipulation is realized for the first time in the antiferromagnetic Weyl semimetal MnSn using the readout signal of anomalous Hall effect in the MnSn/heavy metal (Pt, W) heterostructures. Here, it is reported that the switching of Hall signal can be significantly enhanced by 1) removing the buffer layer of Ru to adjust the crystal orientation of MnSn, and 2) annealing after deposition of the heavy metal to change the interfacial condition. The switching of the Hall resistance is 0.35 Ω in the MnSn/W sample, which becomes one order of magnitude larger than the previously reported value using Ru/MnSn/Pt heterostructures. Moreover, by increasing the read current, it is found that the readout voltage may go well beyond 1 mV, a milestone for future applications in memory technology.
开发一种通过电操纵外尔半金属态的技术是利用拓扑鲁棒特性设计非易失性存储器的关键一步。最近，在反铁磁外尔半金属MnSn中，首次利用MnSn/重金属（Pt、W）异质结构中的反常霍尔效应读出信号实现了这种操纵。在此，据报道，通过以下两种方法可显著增强霍尔信号的切换：1）去除Ru缓冲层以调整MnSn的晶体取向；2）在沉积重金属后进行退火以改变界面条件。在MnSn/W样品中，霍尔电阻的切换为0.35Ω，比之前使用Ru/MnSn/Pt异质结构报道的值大一个数量级。此外，通过增加读取电流，发现读出电压可能远超过1mV，这是未来在存储技术中应用的一个里程碑。
