Coherent Revival of Ramsey Oscillations in the Fluxonium Qubit Coupled to a bath of Harmonic Oscillators

We have realized different Fluxonium qubits in a 2D and 3D structure and find state of the art coherence and relaxation times. We observed an increase of the relaxation time both in 3D and 2D at the optimum point of the qubit, when dissipative quasi-particle tunneling is suppressed.
We aim to realize a 2D fluxonium coupled respectively to 4 and 12 on-chip lumped element resonators. We use a fast flux line to control the coupling between the Fluxonium qubit and the resonators. We have studied theoretically the emerging spin-Boson Hamiltonian for this particular circuit with the aim to measure revival effects in the coherent oscillations of the qubit. We started to implement measurements, revealing the effect of a small harmonic oscillator bath of 4 oscillators on the revival of the quantum coherence.