Resistively-detected microwave resonance in magic-angle twisted bilayer graphene with WSe₂

The direct coupling of radio frequency (RF) fields with electrons enables a powerful method to probe the spin and isospin degrees of freedom associated with the flat energy band in two-dimensional moiré systems. Here we demonstrate resistively detected microwave resonance measured in magic-angle twisted bilayer graphene (tBLG). By creating an atomic interface between tBLG and a tungsten-diselenide (WSe₂) crystal, proximity effect endows spin-orbit coupling (SOC) in the graphene layers, resulting in ferromagnetism at both quarter and half-filling and a rich system tunable by carrier density, temperature, perpendicular electric field, and parallel magnetic field [1]. In such a structure, we observed robust resonance features in the longitudinal resistance at microwave frequency that varies with both the in-plane and out-of-plane magnetic field. Based on the magnetic field-frequency dependence of the resonance feature, we are able to extract key parameters of material properties, such as the Ising and Rashba terms of SOC. Furthermore, the ability to detect microwave resonance using resistive measurement allows us to investigate the dynamics of spin waves and demonstrate magnon modes associated with spin and isospin orders.