Optimizing Fast and High-Sensitivity Semiconductor Qubit Readout Using a Modular Superconducting Resonator Design

Fast and accurate readout of qubits based on semiconductor quantum dots is crucial for advancing quantum information processing. A modular readout assembly offers the flexibility to interface with a range of independently fabricated semiconductor devices. Recent work has demonstrated a minimum integration time of just a few nanoseconds using a modular superconducting resonator design [1]. Building on this approach, we have fabricated high-Q superconducting resonators operating at microwave frequencies to enable fast readout. However, efficiently coupling these resonators to various semiconductor quantum dot structures presents a challenge, as the load impedance—comprising both dissipative and reactive components—can vary significantly between devices. To ensure optimal matching conditions for the microwave resonator, a compensation element is required. In this presentation, we will explore options for integrating a tunable matching element to achieve high-bandwidth and high-sensitivity qubit readout. Additionally, we will present finite element simulations of the modular microwave assembly to further optimize performance.