Topological Sliding Moiré Phononic Crystals

Area of Science:

• Topological physics
• Classical acoustics
• Condensed matter physics

Background:

• Topological physics is expanding into classical systems like photonics and acoustics.
• Existing topological acoustic materials often rely on conventional lattices and specific symmetries.
• A need exists for new designs overcoming these limitations.

Purpose of the Study:

• To introduce a novel design for topological phononic crystals utilizing a moiré superlattice.
• To explore the topological properties and potential applications of sliding moiré phononic crystals.
• To demonstrate the creation of robust topological edge states and localized bulk states.

Main Methods:

• Construction of topological phononic crystals via sliding moiré superlattices.
• Characterization of topological properties using dynamical Chern number.
• Analysis of bulk and edge state behavior under sliding modulation.

Main Results:

• Sliding moiré phononic crystals exhibit nontrivial topology and topological pumping of edge states.
• The topological moiré edge states are insensitive to edge geometry.
• One-dimensional moiré flat bulk bands lead to localized bulk states, forming independent signal channels.

Conclusions:

• The proposed sliding moiré phononic crystals offer a unique platform for topological acoustics.
• These materials enable robust, geometry-independent edge states and localized bulk states.
• Potential applications include advanced acoustic communications and isolation in integrated devices.