We report an experimental study of a Si/SiGe double quantum dot (DQD) directly coupled to a niobium superconducting coplanar stripline microwave resonator. This hybrid architecture enables high-bandwidth dispersive readout suitable for real-time feedback and error-correction protocols. Fast and sensitive readout is achieved primarily by optimizing the DQD gate lever arm, guided by MaSQE quantum dot simulations, which enhances the dispersive signal without requiring high-impedance resonators. We demonstrate a signal-to-noise ratio of unity with an integration time of 34.54 ns, corresponding to a system bandwidth of 14.48 MHz and a charge sensitivity of $1.86\times {10}^{-4}e/\sqrt{\mathrm{Hz}}$. Analysis of the voltage power spectral density (PSD) of the in-phase $(I)$ and quadrature $(Q)$ baseband signals characterizes the system’s readout noise, with the PSD’s dependence on integration time providing insight into distinct physical regimes.

Close

PrevNext

View figure in article

• Optoelectronics
• Quantum information with solid state qubits
• Double quantum dots
• Semiconductor compounds
• Spin qubits
• Microwave techniques
• Radiofrequency reflectometry
• Superconducting RF