Multimode Storage of Quantum Microwave Fields in Electron Spins over 100 ms

Area of Science:

• Quantum computing
• Solid-state physics
• Superconducting circuits

Background:

• Quantum information processing relies on long-lived quantum states.
• Near-surface spins in silicon offer potential for scalable quantum technologies.
• Superconducting resonators are crucial for interfacing with spin qubits.

Purpose of the Study:

• To investigate long coherence times of near-surface bismuth donor electron spins in silicon.
• To demonstrate the storage and retrieval of microwave fields using these spin ensembles.
• To assess the preservation of phase coherence and quantum statistics during storage.

Main Methods:

• Coupling near-surface bismuth donor electron spins to a superconducting microresonator.
• Biasing the spins at a clock transition to enhance coherence.
• Applying a train of weak microwave fields and using a Hahn-echo-like protocol for storage and retrieval.

Main Results:

• Achieved long coherence times of up to 300 milliseconds for bismuth electron spins.
• Demonstrated partial absorption and storage of microwave fields for 100 milliseconds.
• Successfully retrieved the stored microwave fields.
• Confirmed preservation of phase coherence and quantum statistics.

Conclusions:

• Near-surface bismuth donor spins in silicon coupled to superconducting resonators exhibit long coherence times.
• This system enables robust storage and retrieval of quantum information encoded in microwave fields.
• The demonstrated capabilities are promising for advancing solid-state quantum computing and memory applications.