TY - JOUR AU - Viola, Giovanni AU - Catelani, Gianluigi TI - Collective modes in the fluxonium qubit JO - Physical review / B VL - 92 IS - 22 SN - 1098-0121 CY - College Park, Md. PB - APS M1 - FZJ-2015-07865 SP - 224511 PY - 2015 AB - Superconducting qubit designs vary in complexity from single- and few-junction systems, such as the transmon and flux qubits, to the many-junction fluxonium. Here, we consider the question of whether the many degrees of freedom in the fluxonium circuit can limit the qubit coherence time. Such a limitation is in principle possible, due to the interactions between the low-energy, highly anharmonic qubit mode and the higher-energy, weakly anharmonic collective modes. We show that so long as the coupling of the collective modes with the external electromagnetic environment is sufficiently weaker than the qubit-environment coupling, the qubit dephasing induced by the collective modes does not significantly contribute to decoherence. Therefore, the increased complexity of the fluxonium qubit does not constitute by itself a major obstacle for its use in quantum computation architectures. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000367060600005 DO - DOI:10.1103/PhysRevB.92.224511 UR - https://juser.fz-juelich.de/record/280119 ER -