Context
To address the challenge of reconciling superconductor and semiconductor technologies, we brought electrical tuning at the core of superconducting circuits by introducing a gapless semiconductor (or zero-overlap semimetal), graphene, in the key element: the Josephson junction. We have developed an expertise in the fabrication of ultra-high-quality gate-tunable graphene weak links based on van der Waals heterostructures.
Our contribution
Based on such a building block, we have demonstrated the first gate tunable Josephson parametric amplifier [1]. We have shown that we can tune the amplification frequency by about 1GHz with a simple gate voltage while maintaining a quantum limited gain. Currently we work on developing advanced pumping schemes, for instance using three waves mixing, to optimize the performances of the amplifier.
In parallel with our activities on amplifiers, we use the specificity of graphene weak links to build gate-tunable superconducting qubits and we aim at demonstrating long-lived qubits, protected from decoherence.
