Microwave-activated gates between a fluxonium and a transmon qubit
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 flu...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2022-11-01
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| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.4.043127 |
| _version_ | 1797210580990296064 |
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| author | A. Ciani B. M. Varbanov N. Jolly C. K. Andersen B. M. Terhal |
| author_facet | A. Ciani B. M. Varbanov N. Jolly C. K. Andersen B. M. Terhal |
| author_sort | A. Ciani |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-24T10:12:52Z |
| format | Article |
| id | doaj.art-6a0fc2c6f42641deb72c97aa4d22aea8 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:12:52Z |
| publishDate | 2022-11-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-6a0fc2c6f42641deb72c97aa4d22aea82024-04-12T17:26:22ZengAmerican Physical SocietyPhysical Review Research2643-15642022-11-014404312710.1103/PhysRevResearch.4.043127Microwave-activated gates between a fluxonium and a transmon qubitA. CianiB. M. VarbanovN. JollyC. K. AndersenB. M. TerhalWe 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.http://doi.org/10.1103/PhysRevResearch.4.043127 |
| spellingShingle | A. Ciani B. M. Varbanov N. Jolly C. K. Andersen B. M. Terhal Microwave-activated gates between a fluxonium and a transmon qubit Physical Review Research |
| title | Microwave-activated gates between a fluxonium and a transmon qubit |
| title_full | Microwave-activated gates between a fluxonium and a transmon qubit |
| title_fullStr | Microwave-activated gates between a fluxonium and a transmon qubit |
| title_full_unstemmed | Microwave-activated gates between a fluxonium and a transmon qubit |
| title_short | Microwave-activated gates between a fluxonium and a transmon qubit |
| title_sort | microwave activated gates between a fluxonium and a transmon qubit |
| url | http://doi.org/10.1103/PhysRevResearch.4.043127 |
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