Coupling between a Si/SiGe Resonant Exchange Qubit and a High-Impedance Microwave Resonator

Coherent spin-photon coupling is believed to play a significant role in silicon-based quantum computation. The resonant exchange (RX) qubit, formed in a triple quantum dot, is a promising platform for spin-photon coupling and qubit scaling due to the large electric dipole moment and full electrical control without auxiliary micromagnets. However, there has been no experimental demonstration of silicon RX qubits and their strong coupling to microwave photons to date. In this work, we report the strong coupling between an RX qubit and a high-impedance resonator on a Si/SiGe heterostructure with coupling strength g_{s}/(2π)=65.8  MHz and decoherence rate γ_{s}/(2π)=21.4  MHz. Furthermore, the dependence of decoherence rate on detuning is measured and analyzed using a phenomenological model, indicating that the charge noise is the main source of decoherence. Our results demonstrate the viability of RX qubits in silicon, highlighting their crucial role of large-scale qubit integration for silicon quantum computation and opening new possibilities for quantum network.