Selective excitation of superconducting qubits with a shared control line through pulse shaping
R. Matsuda, R. Ohira, T. Sumida, H. Shiomi, A. Machino, S. Morisaka, K. Koike, T. Miyoshi, Y. Kurimoto, Y. Sugita, Y. Ito, Y. Suzuki, P. A. Spring, S. Wang, S. Tamate, Y. Tabuchi, Y. Nakamura, K. Ogawa, M. Negoro · Physical Review Research · 2025
In conventional architectures of superconducting quantum computers, each qubit is connected to its own control line, leading to a commensurate increase in the number of microwave lines as the system scales. Frequency-multiplexed qubit control addresses this problem by enabling multiple qubits to share a single microwave line. However, it can cause unwanted excitation of nontarget qubits, especially when the detuning between qubits is smaller than the pulse bandwidth. Here, we propose a selective-excitation-pulse (SEP) technique that suppresses unwanted excitations by shaping a drive pulse to create null points at nontarget qubit frequencies. In a proof-of-concept experiment with three fixed-frequency transmon qubits, we demonstrate that the SEP technique achieves single-qubit gate fidelities comparable to those obtained with conventional Gaussian pulses while effectively suppressing unwanted excitations in nontarget qubits. These results highlight the SEP technique as a promising tool for enhancing frequency-multiplexed qubit control.