Crosstalk-robust quantum control in multimode bosonic systems

Journal Article · Tue Oct 01 00:00:00 UTC 2024 · Phys.Rev.Applied

DOI: https://doi.org/10.1103/PhysRevApplied.22.044072 · OSTI ID:2504572

You, Xinyuan  ^[1]; Lu, Yunwei  ^[2]; Kim, Taeyoon  ^[3]; Kürkçüog̃lu, Dog̃a Murat  ^[1]; Zhu, Shaojiang  ^[1]; van Zanten, David  ^[1]; Roy, Tanay  ^[1]; Lu, Yao  ^[1]; Chakram, Srivatsan ^[4]; Grassellino, Anna  ^[1]; Romanenko, Alexander  ^[1]; Koch, Jens  ^[2]; Zorzetti, Silvia  ^[1]

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1. Fermilab
2. Northwestern U.
3. Fermilab; Northwestern U.
4. Rutgers U., Piscataway

High-coherence superconducting cavities offer a hardware-efficient platform for quantum information processing. To achieve universal operations of these bosonic modes, the requisite nonlinearity is realized by coupling them to a transmon ancilla. However, this configuration is susceptible to crosstalk errors in the dispersive regime, where the ancilla frequency is Stark shifted by the state of each coupled bosonic mode. This leads to a frequency mismatch of the ancilla drive, lowering the gate fidelities. To mitigate such coherent errors, we employ quantum optimal control to engineer ancilla pulses that are robust to the frequency shifts. These optimized pulses are subsequently integrated into a recently developed echoed conditional displacement protocol for executing single- and two-mode operations. Through numerical simulations, we examine two representative scenarios: the preparation of single-mode Fock states in the presence of spectator modes and the generation of two-mode entangled Bell-cat states. Our approach markedly suppresses crosstalk errors, outperforming conventional ancilla control methods by orders of magnitude. These results provide guidance for experimentally achieving high-fidelity multimode operations and pave the way for developing high-performance bosonic quantum information processors.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Northwestern U.; Rutgers U., Piscataway
• Sponsoring Organization: US Department of Energy
• Grant/Contract Number: 89243024CSC000002; AC02-07CH11359
• OSTI ID: 2504572
• Report Number(s): FERMILAB-PUB-24-0033-SQMS; oai:inspirehep.net:2763678; arXiv:2403.00275
• Journal Information: Phys.Rev.Applied, Journal Name: Phys.Rev.Applied Journal Issue: 4 Vol. 22
• Country of Publication: United States
• Language: English