Resistively-detected microwave resonance as a spin probe in graphene moiré systems

In a strongly correlated system, collective excitations reveal vital information regarding the electronic order of the underlying ground state. A recent report demonstrated a resisitively-detected electron spin resonance (RD-ESR) technique to directly observe collective modes in the form of microwave-induced resonance near half filling of the moiré flatband [1]. The frequency-magnetic field dependence of these resonance modes enabled the extraction of key parameters such as intervalley exchange interaction and spin stiffness. Furthermore, the onset of robust resonance response coinciding with the spontaneous flavor polarization at half moiré filling indicates that the generation and detection of the microwave resonance relies on the strong correlation of the flat band. Here, we apply the RD-ESR technique to twisted trilayer graphene systems that exhibit both superconducting and diode-like nonreciprocal transport response [2]. The ability to rectify the spin characteristics of systems with valley-polarized isospin order represents unlocking a comprehensive spin-valley picture of the electronic order of the ground state.



[1] E. Morissette, J.X. Lin, D. Sun, et al., arXiv:2206.08354 (2022)

[2] J.X. Lin, P. Siriviboon, H.D. Scammel, et al., Nature Physics 18 1221-1227 (2022)

[3] N.J. Zhang, J.X. Lin, Y. Wang, et al., arXiv: 2209.12964 (2022)