Multiqubit gate based on parity cross resonance

Abstract

The realization of multiqubit 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 multicontrol 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 multiqubit interactions as fundamental building blocks for next-generation superconducting quantum processors, thereby enabling improved gate performance with more flexible tuning of circuit parameters.