Current-induced magnetization caused by crystal chirality in nonmagnetic elemental tellurium
Current-induced magnetization caused by crystal chirality in nonmagnetic elemental tellurium
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DOI：
10.1103/physrevresearch.3.023111
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发表时间：
2021-05-10
影响因子：
4.2
通讯作者：
Itou, Tetsuaki
中科院分区：
文献类型：
--
作者：
Furukawa, Tetsuya;Watanabe, Yuta;Itou, Tetsuaki
手性物质的结构缺乏反转对称性、镜像对称性和旋转反射对称性；因此，给定的手性材料具有右手或左手结构。在手性物质中，电和磁可以以超越经典电磁学的奇异方式耦合（例如手性磁体中的磁手性效应）。在本文中，我们对块状非磁性手性物质三方碲中的线性电流感应磁化效应给出了可靠的实验证明。我们测量了脉冲电流下三角碲单晶的 Te-125 核磁共振 (NMR) 谱移。我们提供一般对称性考虑因素来讨论电（电场和电流）感应磁化，并阐明在三角碲中观察到的 NMR 位移是由线性电流感应磁化效应引起的，而不是由高阶磁电效应引起的。我们还表明，电流引起的核磁共振位移通过碲晶体结构的手性反转而逆转。这一结果是晶体手性诱导自旋极化的直接证据，这是手性有机分子中手性诱导自旋选择性的无机块体晶体类似物。目前的研究结果还表明，非磁性手性晶体可以应用于自旋电子学和无线圈器件，以产生超越经典电磁的磁化强度。
Chiral matter has a structure that lacks inversion, mirror, and rotoreflection symmetry; thus, a given chiral material has either a right- or left-handed structure. In chiral matter, electricity and magnetism can be coupled in an exotic manner beyond the classical electromagnetism (e.g., magneto chiral effect in chiral magnets). In this paper, we give a firm experimental proof of the linear electric-current-induced magnetization effect in bulk nonmagnetic chiral matter elemental trigonal tellurium. We measured a Te-125 nuclear magnetic resonance (NMR) spectral shift under a pulsed electric current for trigonal tellurium single crystals. We provide general symmetry considerations to discuss the electrically (electric-field- and electric-current-) induced magnetization and clarify that the NMR shift observed in trigonal tellurium is caused by the linear current-induced magnetization effect, not by a higher-order magnetoelectric effect. We also show that the current-induced NMR shift is reversed by a chirality reversal of the tellurium crystal structure. This result is direct evidence of crystal-chirality-induced spin polarization, which is an inorganic-bulk-crystal analog of the chirality-induced spin selectivity in chiral organic molecules. The present findings also show that nonmagnetic chiral crystals may be applied to spintronics and coil-free devices to generate magnetization beyond the classical electromagnetism.