Longitudinal coupling between a Si/SiGe quantum dot and an off-chip TiN resonator

Abstract

Superconducting cavities have emerged as a key tool for measuring the spin states of quantum dots. So far however, few experiments have explored longitudinal couplings between dots and cavities, and no solid-state qubit experiments have explicitly probed the "adiabatic" regime, where the Purcell decay is strongly suppressed. Here, we report measurements of a double-quantum-dot charge qubit coupled to a high-impedance resonator via a "flip-chip" design geometry. By applying an adiabatic ac drive to the qubit through two different channels, and studying the effects of qubit energy detuning, interdot tunneling, and driving strength, we are able to unequivocally confirm the presence of a longitudinal coupling between the qubit and cavity, while the qubit remains in its ground state. Since this coupling is proportional to the driving amplitude, and is therefore switchable, it has the potential to become a powerful new tool in qubit experiments.

Main text and Supplementary Materials, 16 pages, 10 figures

References in corpus (4)

• Coupling Superconducting Qubits via a Cavity Bus
• Circuit Quantum Electrodynamics with a Spin Qubit
• Strong Coupling of a Single Electron in Silicon to a Microwave Photon
• Control of transition frequency of a superconducting flux qubit by longitudinal coupling to the photon number degree of freedom in a resonator

Cited by in corpus (9)

• Two-qubit logic between distant spins in silicon
• Cavity-mediated entanglement of parametrically driven spin qubits via sidebands
• Unifying Floquet theory of longitudinal and dispersive readout
• Ultra-dispersive resonator readout of a quantum-dot qubit using longitudinal coupling
• A photonic which-path entangler based on longitudinal cavity-qubit coupling
• Parametric longitudinal coupling of a semiconductor charge qubit and a RF resonator
• Spin-photon interaction in a nanowire quantum dot with asymmetrical confining potential
• Parametric Drive of a Double Quantum Dot in a Cavity
• Spin-photon coupling using circular double quantum dots