Nonlinear transport as a probe of spin texture in two-dimensional magnets

The discovery of intrinsic two-dimensional (2D) magnetism has opened a new frontier in quantum materials. However, detecting magnetic order in atomically thin magnets remains challenging, as bulk diffraction methods, such as Neutron diffraction, lack sensitivity, and magneto-optical Kerr rotation is ineffective for in-plane magnets.

We theoretically propose a highly sensitive, all-electrical probe of spin textures in 2D magnets based on nonlinear transport. In magnetic systems, a field-induced deformation of Bloch wave packets generates an intrinsic (scattering-time–independent) nonlinear conductivity governed by the quantum geometry. This response is uniquely sensitive to the simultaneous breaking of time-reversal and inversion symmetries, yielding a detectable hysteretic current that tracks magnetic order. We illustrate this concept using realistic density functional theory for the air-stable semiconducting magnet CrSBr, establishing a pathway for all-electrical detection of spin order in 2D materials.