Spontaneous Hall effect in the magnetic Weyl semimetallic Eu2Ir2O7 (111) thin films

Abstract

Here, we have carried out a low-temperature magnetization and magnetotransport study on epitaxial antiferromagnetic Eu2Ir2O7 (111) thin films with an all-in-all-out/all-out-all-in spin structure to delve into the possibility of realizing spontaneous Hall effect that can provide strong experimental evidence for the existence of the Weyl semimetallic phase. The temperature-dependent resistivity on Eu2Ir2O7 (111) thin films indicates a semimetallic transition below 90 K and the existence of a correlated metallic state in the high-temperature regime (90–300 K). Magnetoresistance measurements suggest that at a low temperature (below 10 K), the all-in-all-out (AIAO) spin structure is stable enough against the applied magnetic field, whereas above 10 K, application of magnetic field causes field-induced modification of the spin structure and plastic domain deformation. Hall resistivity shows a spontaneous Hall effect (SHE) in the low-temperature semimetallic phase of Eu2Ir2O7 (111) thin films with minimal magnetization (AIAO/all-out-all-in spin structure). The observed SHE provides strong evidence for the emergent Weyl semimetallic phase in the (111) thin film geometry of antiferromagnetic Eu2Ir2O7.