Charge state manipulation of qubits in diamond

Area of Science:

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

Background:

• Nitrogen-vacancy (NV) centers in diamond are promising solid-state qubits.
• NV center charge state instability (NV(-) to NV(0)) hinders qubit performance.
• Controlling charge state is essential for stable quantum operations.

Purpose of the Study:

• To demonstrate dynamic control over the charge state of NV centers in diamond.
• To investigate the use of an electrolytic gate for charge state manipulation.
• To explore the potential for accessing different NV charge states, including NV(+)

Main Methods:

• Utilized an electrolytic gate electrode to control the diamond surface Fermi level.
• Performed experiments to switch single NV centers between charge states.
• Employed numerical simulations to confirm the mechanism of charge state manipulation.

Main Results:

• Successfully switched single NV centers from an unknown non-fluorescent state to the NV(0) state.
• Shifted the population of an ensemble of NV centers from NV(0) to the qubit state NV(-).
• Confirmed that gate-controlled Fermi level shifts induce charge state transitions.

Conclusions:

• Electrolytic gating provides a method for dynamic control of NV center charge states.
• This technique allows for switching between NV(-) and NV(0) states, enhancing qubit stability.
• Opens possibilities for exploring novel NV charge states like NV(+) for quantum applications.