A physics rule to design aperiodic width-modulated waveguides for minimum phonon transmission with Bayesian...

Area of Science:

• Nanoscale science and engineering
• Condensed matter physics
• Materials science

Background:

• Aperiodic nano-waveguides (nWVGs) and superlattices (SLs) are more efficient at limiting phonon transmission and heat conduction than periodic structures.
• These structures can mitigate parasitic heat conduction, crucial for nanoscale heat management and energy conversion.

Purpose of the Study:

• To investigate optimal aperiodicity in width-modulated nWVGs for maximum disorder.
• To confirm the physics principle that maximum disorder minimizes thermal conductance in such systems.

Main Methods:

• Development of a feasible optimization problem by reducing complexity.
• Application of efficient Bayesian optimization techniques.
• Quantification of disorder by the number of non-identical modulation units.

Main Results:

• Optimal aperiodicity in width-modulated nWVGs was found to correspond to maximum disorder.
• Results confirmed the physics rule that minimum thermal conductance is achieved with the most disordered arrays.
• The degree of disorder was effectively quantified.

Conclusions:

• Geometrical aperiodicity can be designed to control transmission properties in metamaterials.
• This study provides a route for designing aperiodic structures for enhanced thermal management at the nanoscale.