Selective Excitation of Superconducting Qubits with a Shared Control Line through Pulse Shaping

TL;DR

This paper introduces a pulse shaping technique called SEP that enables selective excitation of superconducting qubits sharing a control line, reducing crosstalk and maintaining high gate fidelity in frequency-multiplexed systems.

Contribution

The paper presents the SEP pulse shaping method that suppresses unwanted qubit excitations, improving frequency-multiplexed control in superconducting quantum computers.

Findings

SEP achieves high-fidelity single-qubit gates

Effective suppression of non-target qubit excitation

Comparable performance to conventional Gaussian pulses

Abstract

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 non-target 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 non-target 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 non-target qubits. These results highlight the SEP technique as a promising tool for enhancing frequency-multiplexed qubit control.