Connected network model for the mechanical loss of amorphous materials

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Modeling

Background:

• Low-frequency dissipation in amorphous solids is often explained by isolated two-level systems (TLS).
• Materials with minimal mechanical or dielectric loss are crucial for advanced technologies like quantum computing and gravitational wave detection.

Purpose of the Study:

• To investigate the energy landscape of amorphous solids beyond the isolated TLS model.
• To develop a new theoretical framework for understanding mechanical loss in amorphous materials.

Main Methods:

• Atomistic modeling of amorphous silicon and titanium dioxide.
• Development of a nonequilibrium thermodynamic theory for mechanical loss in connected networks.

Main Results:

• The energy landscape of amorphous solids is better described as a connected network of inherent structures, not isolated TLS.
• The network connectivity introduces novel mechanisms influencing mechanical loss, with distinct frequency profiles compared to the TLS model.

Conclusions:

• The connected network model challenges the traditional TLS theory for amorphous solid dissipation.
• This new model provides insights for designing amorphous materials with tailored low mechanical loss properties.