Fast room-temperature phase gate on a single nuclear spin in diamond

Area of Science:

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

Background:

• Nuclear spins offer long-lived quantum coherence but are challenging to control rapidly due to small magnetic moments.
• Nitrogen-vacancy (NV) centers in diamond are promising solid-state qubits.

Purpose of the Study:

• To demonstrate a fast and efficient nuclear spin phase gate for controlling qubits within NV centers.
• To enhance the coherence times of nuclear spins through rapid manipulation.

Main Methods:

• Utilized the hyperfine interaction between electron and nuclear spins in a nitrogen-vacancy center.
• Employed off-resonance driving of electron spin transitions to enable the nuclear spin phase gate.
• Implemented a bang-bang decoupling sequence using repeated phase gate applications.

Main Results:

• Achieved a nuclear spin phase gate with a duration of approximately 500 nanoseconds.
• Demonstrated extended spin state locking for up to 140 microseconds through repeated gate applications.
• Successfully decoupled the nuclear spin from environmental noise.

Conclusions:

• The developed nuclear spin phase gate enables fast and precise control of qubits in nitrogen-vacancy centers.
• Rapid gate operations and decoupling sequences can significantly extend quantum coherence times, crucial for quantum computing applications.
• This method overcomes limitations of traditional nuclear magnetic resonance control for solid-state qubits.