Giant magnetic response in layered antiferromagnetic iridate heterostructures

Layered iridates hosting square lattices have recently gained plenty of interests with potential of unconventional superconductivity leading the charge. The large spin-orbit coupling of the Ir pseudospin half state, on the other hand, may enable a hidden SU(2) symmetry much stronger than that in cuprates. Probing and unveiling this symmetry is however hindered in the bulk material, because of the non-trivial interlayer coupling. Through accurately tailoring the magnetic structure, we exploited this symmetry in heterostructures as composed of perovskite SrIrO₃ and SrTiO₃ [1]. Upon approaching the 2D limit, the hidden symmetry triggers large magnetic fluctuations and enables an unprecedentedly strong coupling between the antiferromagnetic order and external magnetic field [2]. The ability of materializing the hidden symmetry in artificial structures provides a fruitful playground for pursuing novel phenomena beyond the cuprate physics.

[1] L. Hao, et.al, Phys. Rev. Lett. 119, 027204 (2017). [2] L. Hao, et.al, Nat. Phys. 14, 806–810 (2018).