Antiferromagnets have emerged as promising spintronic materials due to their ultrafast spin dynamics and zero stray field. While these materials exhibit fascinating magnetoresistance effects, the inherent lack of stray field presents a fundamental duality-enabling high density integration but impeding low-field operation, which has remained a key challenge in the field. In this work, we report enhanced low-field anisotropic magnetoresistance (AMR) in lightly hole-doped $J_{\mathrm{eff}}=1/2$ antiferromagnets ${\mathrm{Sr}}_2{\mathrm{Ir}}_{1-x}{\mathrm{Zn}}_x{\mathrm{O}}_4$, which meanwhile exhibits exceptional angular sensitivity. The large low-field AMR persists across wide temperature ranges and diverse current-direction configurations. This essentially relies on the intrinsic rigidity of the antiferromagnetic phase to hole-doping, evidenced by a slight decrease in the Néel temperature $T_{\mathrm{N}}$ over a broad doping range. The AMR is relevant entirely to crystal symmetry, e.g., a crystalline type effect depending on the magnetocrystalline anisotropy, which is more essentially associated with the low valance state of ${\mathrm{Zn}}^{2+}$.

Close

PrevNext

View figure in article

• Magnetic order
• Magnetotransport
• Spin-orbit coupling
• Antiferromagnets
• Magnetization measurements
• Resistivity measurements
• X-ray diffraction