On-Chip Microwave Frequency Combs in a Superconducting Nanoelectromechanical Device

Area of Science:

• Quantum physics
• Nanoscience
• Microwave engineering

Background:

• Electromechanical systems couple mechanical and microwave components.
• Linear approximations describe basic interactions like cooling and amplification.
• Nonlinear effects emerge at high microwave fields, leading to complex phenomena.

Purpose of the Study:

• To experimentally generate and characterize microwave frequency combs in a superconducting electromechanical device.
• To explore the influence of optomechanical parameters on comb formation and dynamics.
• To validate experimental findings with numerical modeling.

Main Methods:

• Utilized a niobium-based superconducting electromechanical device.
• Excited nanomechanical resonances coupled to a microwave cavity.
• Investigated comb generation under varying detuning, pump powers, and cavity decay rates.

Main Results:

• Observed microwave frequency combs centered at 3.78 GHz.
• Determined comb frequency spacing equal to the mechanical resonant frequency (8 MHz).
• Experimental results demonstrated excellent agreement with numerical simulations.

Conclusions:

• Successfully generated electromechanical microwave frequency combs.
• The observed comb dynamics are well-described by numerical models.
• These combs offer potential for precise electrical tracking in nanomechanical sensing.