Fig. 4: Origin of ME phase transition in the Sr2IrO4/SrTiO3 superlattices.
From: Magnetoelectric phase transition driven by interfacial-engineered Dzyaloshinskii-Moriya interaction
a Schematic illustration of the in-plane Dint vector induced by the z-direction Eeff measured by the BLS. K and −K are the propagation directions of the spin-wave. b, c The microscopic scenario of the ME phase transition. The asymmetric-interface-induced polarization (effective electric field) can be illustrated by the atomic displacement (δ in (b) and δ’ in (c)). The effective electric-field-dependent DMI drives the ME phase transition, where the amplitude of DMI is schematically equivalent to the strength of spring (thin in (b) and thick in (c)). Guided by the theoretical model, the enhancement of the polarization (δ < δ’) and thus interfacial DMI could increase the temperature of the ME phase transition.
