Magnetic Field-Induced Spin Nematic Phase Up to Room Temperature in Epitaxial Antiferromagnetic FeTe Thin Films Grown by Molecular Beam Epitaxy

Electronic nematicity, where strong correlations driveelectronsto align in a way that lowers the crystal symmetry, is ubiquitousamong unconventional superconductors. Understanding the interplayof such a nematic state with other electronic phases underpins thecomplex behavior of these materials and the potential for tuning theirproperties through external stimuli. Here, we report magnetic field-inducedspin nematicity in a model system tetragonal FeTe, the parent compoundof iron chalcogenide superconductors, which exhibits a bicollinearantiferromagnetic order. The studies were conducted on epitaxial FeTethin films grown on SrTiO3(001) substrates by molecularbeam epitaxy, where the bicollinear antiferromagnetic order was confirmedby in situ atomic resolution scanning tunneling microscopyimaging. A 2-fold anisotropy is observed in in-plane angle-dependentmagnetoresistance measurements, indicative of magnetic field-inducednematicity. Such 2-fold anisotropy persists up to 300 K, well-abovethe bicollinear antiferromagnetic ordering temperature of 75 K, indicatinga magnetic field-induced spin nematic phase up to room temperaturein the antiferromagnet FeTe.