Quantum electromechanics on silicon nitride nanomembranes

Area of Science:

• Quantum physics
• Nanotechnology
• Optomechanics

Background:

• Radiation pressure enables coupling of mechanical motion to optical or microwave fields.
• Integrating mechanical, optical, and microwave degrees of freedom is crucial for quantum interconnects.
• Existing platforms face challenges in unifying these diverse quantum systems.

Purpose of the Study:

• To present a novel platform for integrating superconducting microwave circuits with planar acoustic and optical devices.
• To demonstrate enhanced electromechanical coupling for quantum electro-opto-mechanical experiments.
• To achieve significant cooling of mechanical resonators using microwave backaction.

Main Methods:

• Utilizing silicon nitride nanomembranes as an all-in-one substrate.
• Designing planar capacitors with nanoscale vacuum gaps and spiral inductor coils.
• Implementing microwave resonant circuits for strong electromechanical coupling.
• Applying microwave backaction cooling to a nanomechanical resonator.

Main Results:

• Achieved large electromechanical coupling to nanoscale acoustic structures.
• Demonstrated microwave backaction cooling of a 4.48 MHz mechanical resonance to an occupancy of 0.32.
• Realized microwave resonant circuits with femtoFarad motional capacitance.

Conclusions:

• Silicon nitride nanomembranes provide a viable platform for integrated quantum electro-opto-mechanical systems.
• The demonstrated coupling and cooling are significant steps towards building quantum interconnects.
• This platform facilitates future research in hybrid quantum systems.