Magnetic control of nonreciprocal charge transport

Nonreciprocal charge transport (NCT) characterized by unequal resistances for opposite current direction enriches the fundamental physics of electron transport and is promising for potential device applications. Here, we report on a study on the magnetic control of the NCT in two-dimensional systems with different types of spin-orbit coupling (SOC). Based on the Boltzmann transport theory, we first study this effect using a general Hamiltonian model and show that the nonlinear conductivity can be efficiently tuned by the exchange field. In particular, the exchange-field orientation dependence of the nonlinear conductivity reveals significantly distinct relations for different SOCs. We further derive the analytical expressions with the weak-field approximation, which are in good accordance with numerical results. Then, we exemplify this phenomenon in the Ag₂Te/Cr₂O₃ surface based on density functional theory calculations. We predict that the nonlinear conductivity in such a system strongly depends on the surface magnetization orientation of the Cr₂O₃ layer. Those findings also suggest that measuring the NCT as a function of the exchange-field orientation provides a simple electrical means to quantify the SOC type. Our results are expected to provide a valuable insight into the NCT physics and open avenues for future rectifying devices.