Towards Developing a Graphene Josepheson junction based qubit device

Construction of Josepheson weak links is an integral part of superconducting quantum devices. New junction structures have various potential applications as new qubits or sensors. We will discuss the preliminary development of a transmon with a graphene based Josepheson junction. The devices are fabricated using epitaxially grown graphene, transferred to a sapphire base with standard lithographic techniques used for junction and antenna layout. The junctions are designed to have 0.3-0.85 nA critical currents and antenna geometry for device resonances between 2-6 GHz and are imbedded in a high Q 3D cavity at 7.7 GHz.