Circuit Quantum Electrodynamics Architecture for Gate-Defined Quantum Dots in Silicon

TL;DR

This paper presents a silicon-based quantum dot device integrated with a superconducting microwave cavity, demonstrating effective charge-photon coupling suitable for quantum information applications.

Contribution

It introduces a hybrid silicon quantum dot architecture with on-chip microwave readout, achieving high quality factors and strong charge-cavity coupling.

Findings

Achieved a cavity quality factor Q of 5,400.

Measured a charge-cavity coupling rate g_c/2pi of 23 MHz.

Demonstrated effective coupling of electrons in silicon quantum dots to microwave photons.

Abstract

We demonstrate a hybrid device architecture where the charge states in a double quantum dot (DQD) formed in a Si/SiGe heterostructure are read out using an on-chip superconducting microwave cavity. A quality factor Q = 5,400 is achieved by selectively etching away regions of the quantum well and by reducing photon losses through low-pass filtering of the gate bias lines. Homodyne measurements of the cavity transmission reveal DQD charge stability diagrams and a charge-cavity coupling rate g_c/2pi = 23 MHz. These measurements indicate that electrons trapped in a Si DQD can be effectively coupled to microwave photons, potentially enabling coherent electron-photon interactions in silicon.