Sep 20 – 25, 2026
University of Graz
Europe/Vienna timezone

Multiqubit gate based on parity cross resonance

Sep 21, 2026, 5:00 PM
15m
HS 15.13 (University of Graz)

HS 15.13

University of Graz

15 - RESOWI E, 1st floor
3) Contributed talk M10 - Mesoscopic superconductivity and quantum circuits Mini-Colloquium

Speaker

Xuexin Xu (Forschungszentrum Jülich)

Description

The realization of multi-qubit entangling gates is essential for efficient, scalable, and fault-tolerant quantum information processing, reducing algorithmic complexity and circuit depth. We demonstrate a native three-qubit entangling gate implemented by simultaneously driving all qubits at a common frequency, exploiting engineered interactions to realize multi-control operations in a single coherent step. By optimizing the conditional dynamics originating from drive-induced nonlocal contamination, desired interaction channels are selectively enhanced while spurious terms are suppressed, ensuring robust performance within the computational subspace. This gate enables key
applications, including deterministic GHZ-state generation, Toffoli-class logic with a shortest gate duration of 90 ns and a highest fidelity of 99.72%, and a controlled-ZZ gate tailored for fast surface-code quantum error correction. Simulations based on realistic IBM device parameters indicate that the gate maintains high fidelity and resilience under increasing excitation numbers and larger Hilbert-space dimensions. Our results establish a foundation for co-designing circuit architectures and control strategies that harness native multi-qubit interactions as fundamental building blocks for next-generation superconducting quantum processors, thereby enabling improved gate performance with more flexible tuning of circuit parameters.

Author

Xuexin Xu (Forschungszentrum Jülich)

Co-authors

Mohammad H. Ansari (Forschungszentrum Jülich) Ms Radhika Joshi (Forschungszentrum Jülich) Rihan Hai (Delft University of Technology) Ms Siyu Wang (Forschungszentrum Jülich)

Presentation materials

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