Moon Jisoo, Zou Qiang, Zhang Huimin, van 't Erve Olaf M J, Combs Nicholas G, Li Lian, Li Connie H
Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375, United States.
Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26505, United States.
ACS Nano. 2023 Sep 12;17(17):16886-16894. doi: 10.1021/acsnano.3c03880. Epub 2023 Aug 18.
Electronic nematicity, where strong correlations drive electrons to align in a way that lowers the crystal symmetry, is ubiquitous among unconventional superconductors. Understanding the interplay of such a nematic state with other electronic phases underpins the complex behavior of these materials and the potential for tuning their properties through external stimuli. Here, we report magnetic field-induced spin nematicity in a model system tetragonal FeTe, the parent compound of iron chalcogenide superconductors, which exhibits a bicollinear antiferromagnetic order. The studies were conducted on epitaxial FeTe thin films grown on SrTiO(001) substrates by molecular beam epitaxy, where the bicollinear antiferromagnetic order was confirmed by atomic resolution scanning tunneling microscopy imaging. A 2-fold anisotropy is observed in in-plane angle-dependent magnetoresistance measurements, indicative of magnetic field-induced nematicity. Such 2-fold anisotropy persists up to 300 K, well-above the bicollinear antiferromagnetic ordering temperature of 75 K, indicating a magnetic field-induced spin nematic phase up to room temperature in the antiferromagnet FeTe.
电子向列性，即强关联作用驱使电子以降低晶体对称性的方式排列，在非常规超导体中普遍存在。理解这种向列态与其他电子相之间的相互作用，是这些材料复杂行为以及通过外部刺激调节其性质潜力的基础。在此，我们报道了在四方结构的FeTe（铁硫族超导体的母体化合物，呈现双线性反铁磁序）这一模型体系中磁场诱导的自旋向列性。研究是在通过分子束外延生长在SrTiO(001)衬底上的外延FeTe薄膜上进行的，其中双线性反铁磁序通过原子分辨率扫描隧道显微镜成像得以证实。在面内角度依赖磁阻测量中观察到二倍对称性，这表明存在磁场诱导的向列性。这种二倍对称性一直持续到300 K，远高于75 K的双线性反铁磁有序温度，表明在反铁磁体FeTe中存在高达室温的磁场诱导自旋向列相。
