Electric field control of superconductivity and quantized anomalous Hall effects in rhombohedral tetralayer graphene – Part 1

Inducing superconducting correlations in chiral edge states is predicted to generate topologically protected modes with exotic quantum statistics. Past experimental efforts have focused on engineering interfaces between superconducting materials and quantum Hall systems. Here, we present rhombohedral tetralayer graphene as an ideal platform for these hybrid interfaces leveraging the gate-tuned ground states between intrinsic superconductors and quantum anomalous Hall states.

In the first of two talks, we present the basic characterizations of the superconductivity and quantized anomalous Hall state. We find multiple superconducting states, including one phase with critical temperature Tc = 55mK at superlattice filling ν≈ −3.5 for layer polarization corresponding to a weak moire potential. Quantized anomalous Hall effect occurs at ν = −1 for weak moire potential, with a measured Chern number |C| = 4. Remarkably, gate voltage can also trigger nonvolatile switching of chirality in the quantum anomalous Hall state, enabling reconfiguration of topological edge mode networks in devices with local gate. These findings open new possibilities for hybrid interfaces between superconductors and topological edge states in the low-disorder limit.