Coherent spin-photon coupling using a resonant exchange qubit

Area of Science:

• Quantum Information Science
• Solid-State Physics
• Quantum Computing

Background:

• Electron spins are promising for quantum computation due to long coherence times.
• Coherent coupling of distant spins is essential for scalable quantum information processing.
• Photons can serve as carriers for quantum information, enabling remote spin interactions.

Purpose of the Study:

• To demonstrate strong coupling between single microwave photons and a three-electron spin qubit.
• To investigate the qubit-photon coupling strength and qubit decoherence rates.
• To explore electrostatic tuning of qubit decoherence and its dependence on the qubit's electric dipole moment.

Main Methods:

• Utilizing a niobium titanium nitride high-impedance resonator and a gallium arsenide device with three quantum dots.
• Observing vacuum Rabi mode splitting as evidence of strong coupling.
• Employing the AC Stark effect to measure qubit-photon coupling strength dependence.

Main Results:

• Achieved strong coupling between single microwave photons and a three-electron spin qubit.
• Observed a coherent coupling strength of approximately 31 MHz and a qubit decoherence rate of about 20 MHz.
• Demonstrated electrostatic tuning of decoherence to a minimal rate of ~10 MHz for a coupling strength of ~23 MHz.

Conclusions:

• The demonstration of strong qubit-photon coupling is a significant advancement for coherent long-distance spin qubit coupling.
• This work paves the way for scalable quantum networks and distributed quantum computation using spin qubits.
• The ability to tune coupling and decoherence electrostatically offers precise control over quantum systems.