TY - JOUR AU - Houzet, M. AU - Serniak, K. AU - Catelani, G. AU - Devoret, M. H. AU - Glazman, L. I. TI - Photon-Assisted Charge-Parity Jumps in a Superconducting Qubit JO - Physical review letters VL - 123 IS - 10 SN - 1079-7114 CY - College Park, Md. PB - APS M1 - FZJ-2019-04580 SP - 107704 PY - 2019 AB - We evaluate the rates of energy and phase relaxation of a superconducting qubit caused by stray photons with energy exceeding the threshold for breaking a Cooper pair. All channels of relaxation within this mechanism are associated with the change in the charge parity of the qubit, enabling the separation of the photon-assisted processes from other contributions to the relaxation rates. Among the signatures of the new mechanism is the same order of rates of the transitions in which a qubit loses or gains energy, which is in agreement with recent experiments. Our theory offers the possibility to characterize the electromagnetic environment of superconducting devices at the single-photon level for frequencies above the superconducting gap. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000485201800019 DO - DOI:10.1103/PhysRevLett.123.107704 UR - https://juser.fz-juelich.de/record/865015 ER -