Cross-Cross Resonance Gate

2021/11/16 by Kentaro Heya, Naoki Kanazawa · 1 voice · 1 citation
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena

paper · pdf · doi:10.1103/prxquantum.2.040336

openalex publication_date 2021/11/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11

Abstract

The implementation of high-fidelity swapping operations is of vital importance for executing quantum algorithms on a quantum processor with limited connectivity. We present an efficient pulse-control technique, the cross-cross resonance (CCR) gate, to implement iSWAP and SWAP gates with dispersively coupled fixed-frequency transmon qubits. The key to the operation of the CCR gate is the simultaneous driving of both of the coupled qubits at the frequency of another qubit, whereby a fast two-qubit interaction roughly equivalent to ZX + XZ entangling gates is realized without strongly driving the qubits. We develop a calibration technique for the CCR gate and evaluate the performance of the iSWAP and SWAP gates. The CCR gate shows remarkable improvements in the average gate error from the conventional decomposition based on the cross-resonance gate.

Citations

• A simple formula for the average gate fidelity of a quantum dynamical operation
• Relation between the Anderson and Kondo Hamiltonians
• State preservation by repetitive error detection in a superconducting quantum circuit

Cited by

• Microwave-activated high-fidelity three-qubit gate scheme for fixed-frequency superconducting qubits

Discussions

• In theory, yes. If the system is ideal, there's only one interacting term( $\sigma^z_1\sigma^x_2$ ) in CR gate. And $a_x$ will be the only non-zero interacting term in Hamiltonian tomography. However, [stackexchange, 0 points]