Tamanna Afrin N, Lakra Ayesha, Ding Xiaxin, Buzi Entela, Park Kyungwha, Sobczak Kamil, Deng Haiming, Sharma Gargee, Tewari Sumanta, Krusin-Elbaum Lia
Department of Physics, The City College of New York-CUNY, New York, NY, 10031, USA.
Department of Physics, Virginia Tech, Blacksburg, VA, 24061, USA.
Nat Commun. 2024 Nov 13;15(1):9830. doi: 10.1038/s41467-024-53319-w.
Chirality - a characteristic handedness that distinguishes 'left' from 'right'-is a fundamental property of quantum particles under broken symmetry intimately connected to their spins. Chiral fermions have been identified in Weyl semimetals through their unique electrodynamics arising from 'axial' charge imbalance between pairs of chiral Weyl nodes-the topologically protected 'relativistic' crossings of electronic bands. Chiral magnetotransport phenomena critically depend on the details of electronic band structure. However, the putative emergence of chiral electronic channels through shape altering of Weyl nodes is yet to be revealed. Here, we detect chirality-endowed linear conduction channels promoted by a tilt of Weyl bands in inversion-symmetric Weyl ferromagnet MnSbTe. The tuning of Weyl nodes is controlled with ionic hydrogen, which heals the system's (Mn-Te) bond disorder and lowers the internode scattering. The reshaped Weyl states feature a doubled Curie temperature ≳50 K and a strong angular transport chirality synchronous with a rare field-antisymmetric longitudinal resistance-a low-field tunable 'chiral switch' that is rooted in the interplay of Berry curvature, chiral anomaly and a hydrogen-mediated form of Weyl nodes.
手性——一种区分“左”与“右”的特征手征性——是量子粒子在对称性破缺下与它们的自旋紧密相关的基本属性。通过手性外尔节点对之间“轴向”电荷不平衡所产生的独特电动力学,在手性外尔半金属中已识别出手性费米子,这些节点是电子能带拓扑保护的“相对论性”交叉点。手性磁输运现象严重依赖于电子能带结构的细节。然而,通过外尔节点形状改变而产生的手性电子通道尚未被揭示。在此,我们在具有反演对称性的外尔铁磁体MnSbTe中检测到由外尔能带倾斜促进的具有手征性的线性传导通道。外尔节点的调控由离子氢控制,离子氢修复了系统的(Mn-Te)键无序并降低了节点间散射。重塑的外尔态具有翻倍的居里温度≳50 K以及与罕见的场反对称纵向电阻同步的强角向输运手征性,这是一种低场可调的“手性开关”,其根源在于贝里曲率、手征反常以及氢介导的外尔节点形式之间的相互作用。