Print Email Facebook Twitter Microwave-activated gates between a fluxonium and a transmon qubit Title Microwave-activated gates between a fluxonium and a transmon qubit Author Ciani, A. (TU Delft QCD/Terhal Group; TU Delft QuTech Advanced Research Centre; Forschungszentrum Jülich GmbH) Varbanov, B.M. (TU Delft QCD/Terhal Group; TU Delft QuTech Advanced Research Centre) Jolly, N.E.A. (TU Delft QCD/Terhal Group; TU Delft QuTech Advanced Research Centre; PSL Research University) Andersen, C.K. (TU Delft Andersen Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Terhal, B.M. (TU Delft QCD/Terhal Group; TU Delft Quantum Computing; TU Delft QuTech Advanced Research Centre; Forschungszentrum Jülich GmbH) Date 2022 Abstract We propose and analyze two types of microwave-activated gates between a fluxonium and a transmon qubit, namely a cross-resonance (CR) and a CPHASE gate. The large frequency difference between a transmon and a fluxonium makes the realization of a two-qubit gate challenging. For a medium-frequency fluxonium qubit, the transmon-fluxonium system allows for a cross-resonance effect mediated by the higher levels of the fluxonium over a wide range of transmon frequencies. This allows one to realize the cross-resonance gate by driving the fluxonium at the transmon frequency, mitigating typical problems of the cross-resonance gate in transmon-transmon chips related to frequency targeting and residual ZZ coupling. However, when the fundamental frequency of the fluxonium enters the low-frequency regime below 100MHz, the cross-resonance effect decreases leading to long gate times. For this range of parameters, a fast microwave CPHASE gate can be implemented using the higher levels of the fluxonium. In both cases, we perform numerical simulations of the gate showing that a gate fidelity above 99% can be obtained with gate times between 100 and 300ns. Next to a detailed gate analysis, we perform a study of chip yield for a surface code lattice of fluxonia and transmons interacting via the proposed cross-resonance gate. We find a much better yield as compared to a transmon-only architecture with the cross-resonance gate as native two-qubit gate. To reference this document use: http://resolver.tudelft.nl/uuid:9b38aa58-340a-481e-a771-bb834fb1314e DOI https://doi.org/10.1103/PhysRevResearch.4.043127 ISSN 2643-1564 Source Physical Review Research, 4 (4) Part of collection Institutional Repository Document type journal article Rights © 2022 A. Ciani, B.M. Varbanov, N.E.A. Jolly, C.K. Andersen, B.M. Terhal Files PDF PhysRevResearch.4.043127.pdf 1.74 MB Close viewer /islandora/object/uuid:9b38aa58-340a-481e-a771-bb834fb1314e/datastream/OBJ/view