Exceptional points enhance sensing in silicon micromechanical resonators

Area of Science:

• Physics
• Materials Science
• Engineering

Background:

• Exceptional points (EPs) are a powerful tool for enhancing the response of open physical systems.
• These systems exhibit a strong response to minor perturbations when operating at EPs.
• Silicon micromechanical resonators are widely used in sensing applications.

Purpose of the Study:

• To demonstrate a method for enhancing the sensitivity of silicon resonant sensors using EPs.
• To investigate the behavior of parity-time (PT)-symmetric dimers at EPs under perturbation.
• To assess the signal-to-noise ratio and spectral properties of EP-enhanced sensing.

Main Methods:

• Utilized a pair of mechanically coupled silicon micromechanical resonators forming a PT-symmetric dimer.
• Operated the resonators at EPs to engineer their response.
• Introduced small perturbations to the mechanically coupled spring and measured frequency splitting.

Main Results:

• Achieved enhanced sensitivity in silicon resonant sensors by operating at EPs.
• Observed frequency splitting from EPs into the PT-symmetric regime upon perturbation, scaling with the square root of perturbation strength.
• Demonstrated a significantly improved signal-to-noise ratio despite a slight increase in noise spectral density.

Conclusions:

• The developed method effectively enhances the sensitivity of silicon resonant sensors.
• EP-based sensing offers a promising approach for achieving ultrahigh sensitivity.
• This work paves the way for next-generation resonant sensors with superior performance.