A Magnetic Field Compatible Graphene Transmon

Hybrid circuit QED is a key tool for readout and scaling of both semiconductor-based spin and topological quantum computing schemes. However, traditional approaches to circuit QED are incompatible with the strong external magnetic fields required for these qubits. We present previous work on superconducting CPW resonators and graphene SNS Josephson junctions that are engineered to survive parallel applied fields up to 6 T. We then combine these elements to realise a magnetic field compatible transmon qubit operating at 1 T. These experiments open up the possibility of fast charge parity measurements in high magnetic fields for readout of Majorana qubits