Quirk Nicholas P, Cheng Guangming, Manna Kaustuv, Felser Claudia, Yao Nan, Ong N P
Department of Physics, Princeton University, Princeton, NJ, 08544, USA.
Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, NJ, 08544, USA.
Nat Commun. 2023 Oct 18;14(1):6583. doi: 10.1038/s41467-023-42222-5.
Weyl semimetals exhibit exotic magnetotransport phenomena such as the chiral anomaly and surface-to-bulk quantum oscillations (Weyl orbits) due to chiral bulk states and topologically protected surface states. Here we report a unique transport property in crystals of the ferromagnetic nodal-line Weyl semimetal CoMnGa that have been polished to micron thicknesses using a focused ion beam. These thin crystals exhibit a large planar resistance anisotropy (10 × ) with axes that rotate by 90 degrees between opposite faces of the crystal. We use symmetry arguments and electrostatic simulations to show that the observed anisotropy resembles that of an isotropic conductor with surface states that are impeded from hybridization with bulk states. The origin of these states awaits further experiments that can correlate the surface bands with the observed 90° twist.
外尔半金属由于其手性体态和拓扑保护的表面态而呈现出奇异的磁输运现象，如手征反常和表面到体的量子振荡（外尔轨道）。在此，我们报道了一种在铁磁节线外尔半金属CoMnGa晶体中独特的输运性质，该晶体已使用聚焦离子束抛光至微米厚度。这些薄晶体表现出较大的平面电阻各向异性（10倍），其轴在晶体相对面之间旋转90度。我们使用对称性论证和静电模拟表明，观察到的各向异性类似于具有表面态且表面态与体态杂化受阻的各向同性导体的各向异性。这些态的起源有待进一步实验来将表面能带与观察到的90°扭转联系起来。
