Acoustic Valley Filter, Valve, and Diverter.

Area of Science:

• Acoustics
• Condensed Matter Physics
• Materials Science

Background:

• Valley degrees of freedom in electronic and classical waves have spurred the field of valleytronics.
• Practical implementation of valley-based devices remains a significant challenge.

Purpose of the Study:

• To realize practical valley devices for acoustic waves, including filters, valves, and diverters.
• To leverage the design and fabrication flexibility of phononic crystals for acoustic valleytronics.

Main Methods:

• Designing and fabricating phononic crystal structures with specific input/output ports and channels.
• Utilizing narrow phononic crystal channels to selectively allow propagation of single valley polarizations.
• Configuring channel structures to achieve filtering, switching (valves), and partitioning (diverters) of acoustic energy flow.

Main Results:

• Demonstrated phononic crystal structures acting as valley filters, enabling valley-polarized acoustic currents.
• Developed valley valves capable of switching acoustic valley-polarized currents by using channels with opposite polarization propagation.
• Implemented valley diverters with branched channels to partition acoustic energy flow based on valley polarization.

Conclusions:

• Phononic crystals offer a viable platform for creating advanced acoustic valley devices.
• The demonstrated filters, valves, and diverters represent a significant step towards practical acoustic valleytronics.
• These findings provide a foundation for future development of sophisticated acoustic wave manipulation devices.