Toward Programmable Quantum Processors Based on Spin Qubits with Mechanically Mediated Interactions and Transport.

Area of Science:

• Quantum Information Science
• Materials Science
• Nanotechnology

Background:

• Solid-state spin qubits, like nitrogen-vacancy (NV) centers in diamond, are promising for quantum computing.
• Achieving controlled interactions and entanglement in large multiqubit systems remains a significant challenge.

Purpose of the Study:

• To present a novel method for programmable control and entanglement of multiqubit spin systems.
• To explore the coupling of NV-center qubits with nanomechanical resonators for quantum information processing.

Main Methods:

• Coupling individual NV centers in diamond nanopillars to magnetically functionalized silicon nitride mechanical resonators.
• Utilizing mechanical transport of qubits for programmable connectivity.
• Characterizing mechanical properties and magnetic field gradients of the nanomechanical system.
• Demonstrating coherent spin qubit manipulation and detecting time-varying magnetic fields using NV centers.

Main Results:

• Achieved a spin-mechanical coupling of 7.7(9) Hz between an NV center and an oscillating micromagnet.
• Demonstrated coherent manipulation of a spin qubit in proximity to a transported micromagnet.
• Verified the feasibility of using nanomechanical resonators for qubit entanglement and programmable connectivity.

Conclusions:

• The proposed method offers a new pathway for scalable quantum information processing with solid-state spin qubits.
• Realistic improvements can lead to reaching the high-cooperativity regime, crucial for advanced quantum applications.
• This work paves the way for enhanced control and entanglement in multiqubit systems.