Relaxation and decoherence of 2D fluxonium

High anharmonicity and wide frequency tunability of the Fluxonium qubit make it an indispensable candidate for emerging quantum computers. Moreover fluxonium qubit in a 3D cavity or environment, when biased at sweet spot, shows very high relaxation time well above 1ms with a potential to achieve higher magnitude [1]. However, 2D and on-chip qubits are more favorable to scale up. The transition from 3D to 2D is not trivial as the coupling to the unwanted degrees of freedom increases a lot. In this work we coupled the fluxonium qubit to on-chip lumped element and distributed resonators. We have studied effect of different qubit parameters on the coherence times T1 and T2.

[1] Ioan M. Pop et al., Nature 508, 369-372 (2014)