|Title||High-Coherence Fluxonium Qubit|
|Publication Type||Journal Article|
|Year of Publication||2019|
|Authors||L. B. Nguyen, Y-H. Lin, A. Somoroff, R. Mencia, N. Grabon, and V. E. Manucharyan|
|Journal||Phys. Rev. X|
|Date Published||NOV 25|
|Type of Article||Article|
We report superconducting fluxonium qubits with coherence times largely limited by energy relaxation and reproducibly satisfying T-2 > 100 mu s (T-2 > 400 mu s in one device). Moreover, given the state-of-the-art values of the surface loss tangent and the 1/f flux-noise amplitude, the coherence time can be further improved beyond 1 ms. Our results violate a common viewpoint that the number of Josephson junctions in a superconducting circuit-over 10(2) here-must be minimized for best qubit coherence. We outline how the unique to fluxonium combination of long coherence time and large anharmonicity can benefit both gate-based and adiabatic quantum computing.