Fu Yu, Li Jing, Papin Jules, Noël Paul, Teresi Salvatore, Cosset-Chéneau Maxen, Grezes Cécile, Guillet Thomas, Thomas Candice, Niquet Yann-Michel, Ballet Philippe, Meunier Tristan, Attané Jean-Philippe, Fert Albert, Vila Laurent
Université Grenoble Alpes, CEA, CNRS, SPINTEC, F-38054, Grenoble, France.
Université Grenoble Alpes, CEA, Leti, F-38000, Grenoble, France.
Nano Lett. 2022 Oct 12;22(19):7867-7873. doi: 10.1021/acs.nanolett.2c02585. Epub 2022 Sep 22.
Spin-orbit effects appearing in topological insulators (TI) and at Rashba interfaces are currently revolutionizing how we can manipulate spins and have led to several newly discovered effects, from spin-charge interconversion and spin-orbit torques to novel magnetoresistance phenomena. In particular, a puzzling magnetoresistance has been evidenced as bilinear in electric and magnetic fields. Here, we report the observation of bilinear magnetoresistance (BMR) in strained HgTe, a prototypical TI. We show that both the amplitude and sign of this BMR can be tuned by controlling with an electric gate the relative proportions of the opposite contributions of opposite surfaces. At magnetic fields of 1 T, the magnetoresistance is of the order of 1% and has a larger figure of merit than previously measured TIs. We propose a theoretical model giving a quantitative account of our experimental data. This phenomenon, unique to TI, offers novel opportunities to tune their electrical response for spintronics.
拓扑绝缘体（TI）以及Rashba界面中出现的自旋轨道效应，正在彻底改变我们操控自旋的方式，并引发了一些新发现的效应，从自旋电荷相互转换、自旋轨道转矩到新型磁阻现象。特别是，一种令人困惑的磁阻已被证明在电场和磁场中呈双线性。在此，我们报告了在典型的TI材料——应变HgTe中对双线性磁阻（BMR）的观测。我们表明，通过电栅极控制相反表面相反贡献的相对比例，可以调节这种BMR的幅度和符号。在1 T的磁场下，磁阻约为1%，并且具有比先前测量的TI材料更大的品质因数。我们提出了一个理论模型，对我们的实验数据进行了定量解释。这种TI特有的现象为自旋电子学中调节其电响应提供了新的机会。
