Casimir probe based upon metallized high Q SiN nanomembrane resonator

Area of Science:

• Physics
• Materials Science
• Nanotechnology

Background:

• The Casimir force, a quantum electrodynamic effect, is crucial for understanding micro/nanoscale interactions.
• Accurate measurement of the Casimir force is challenging due to its small magnitude and environmental sensitivities.

Purpose of the Study:

• To develop and characterize a novel Casimir force probe capable of measurements across microscale and macroscale.
• To achieve high force gradient resolution for sensitive detection of the Casimir force.
• To integrate surface potential measurement capabilities for comprehensive surface analysis.

Main Methods:

• Utilized a metallized, high-quality factor silicon nitride nanomembrane resonator as a force probe.
• Employed a fiber interferometer for precise readout of nanomembrane oscillations.
• Implemented a phase-locked loop scheme for tracking resonance frequency shifts.
• Configured a sphere-plane setup with the nanomembrane acting as the bottom electrode.

Main Results:

• Achieved a force gradient resolution of 3 μN/m.
• Attained a frequency resolution down to 2 × 10⁻⁹.
• Demonstrated the probe's capability for bridging microscale and macroscale Casimir force measurements.
• Successfully integrated Kelvin probe functionality for in situ surface potential imaging.

Conclusions:

• The developed Casimir force probe offers unprecedented sensitivity and versatility.
• The nanomembrane resonator design enhances measurement precision and stability.
• The integrated Kelvin probe capability provides valuable complementary surface information.