Nonlinear nonreciprocal transport in antiferromagnets free from spin-orbit coupling

We theoretically propose a realization of nonlinear nonreciprocal transport in antiferromagnets without relying on the relativistic spin-orbit coupling. Through symmetry and microscopic model analyses, we show that a local spin scalar chirality inducing an asymmetric band modulation becomes a source of a Drude-type nonlinear transport, while an electric polarization induced by a collinear spin configuration in a triangle unit leads to a Berry-curvature-dipole-type nonlinear transport. We demonstrate 120 degrees antiferromagnetic ordering on a triangular lattice and a breathing kagome lattice in an external magnetic field as typical examples. Our results open another direction for the design and engineering of functional materials to show rich parity-violating transport phenomena induced by spontaneous magnetic phase transitions even without the spin-orbit coupling.