Tunable Multi-qubit couplers with low residual ZZ interactions
ORAL
Abstract
Maintaining high gate fidelities when scaling quantum processors to a large number of qubits is key to practically useful quantum computing. Two-qubit gates based on tunable couplers now reach fidelities above 99.5% in superconducting qubit quantum processors, in which the qubits are typically arranged on a square grid with pair-wise qubit-qubit couplers. However, involving multi-qubit couplers that provide higher connectivity may lead to more efficient algorithms. In this work, we specifically discuss the challenges imposed by residual ZZ interactions in such multi-qubit tunable-coupler architectures. We analyze possibilities to suppress these off-resonant interactions by connecting qubits to the coupler with different polarities of the coupling. Moreover, we investigate the use of additional two-qubit couplers as a way to mitigate ZZ interactions.
*We acknowledge the support received from the QUSTEC program funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement number 847471 and from the German Federal Ministry of Education and Research funding program quantum technologies - from basic research to the market under the contract number 13N15680 (GeQCoS).
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Presenters
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Ivan Tsitsilin
- Walther-Meißner-Institut, Munich
- Walther-Meißner-Institut, Bavarian Academy of Sciences and Humanities