Title：Rich phase diagram of layered iridates upon artificial engineering

Speaker：Hao Lin University of Chinese Academy of Sciences

Time：Sep 15 ,2022 12:30

Online report（Tencent ID:283 558 136）

Abstract：While manipulation of antiferromagnetic (AFM) order arises to the forefront of spintronics, it is a long-standing fundamental problem of correlated electron physics. In this talk, I will present couple exciting findings in the strong spin-orbit coupled correlated system, layered iridates. A series of artificial layered iridates [(SrIrO3)1/(SrTiO3)m] were prepared to engage with a staggered magnetic field effect due to the strong spin-orbit interaction. By tuning the SrTiO3 spacer, the AFM structure of the Mott insulating state can be engineered. Upon driving the AFM structure to the two-dimensional limit at m = 2, a hidden SU(2) symmetry is achieved, which was first proposed in cuprates but never experimentally realized. As a result, while the ordering temperature is significantly reduced by strong critical fluctuations, the staggered magnetic field effect allows an external field to greatly suppress the AFM fluctuations and enable a giant response of the AFM order. With a partially released charge degree of freedom at m = 1, the staggered magnetic field effect leads to an intriguing positive anomalous magnetoresistance that probes the AFM susceptibility, because of the strong interplay between charge and longitudinal spin fluctuations. After introducing a gauge-invariant spin-dependent hopping on the square lattice, an exceptionally large magnon gap and an interesting anomalous Hall effect were obtained, highlighting the intriguing correlation-topology interplay in the intermediate regime.