In solid-state physics, phonons — quantized acoustic waves — are traditionally disparaged as major sources of decoherence. However, recent advancements in nanoengineering have allowed the possibility of employing phonons deliberately, taking advantage of their capacity to interface with multiple excitations, such as electrons, photons, and excitons, by changing the atomic positions in a solid.

Priya et al. provided an overview of this new strategy and described potential applications in nanophononics.

“In recent years phonons have gone from being the bad guys in solid-state physics to being main actors unveiling novel physical phenomena,” said author Daniel Lanzillotti-Kimura. “The fact that we can manipulate and engineer acoustic waves of a few nanometer wavelengths is amazing and opens up infinite possibilities.”

For example, the strong coupling between phonons and other excitations could be employed in quantum communication and the storage and transmission of information. Phonons could also be used in the construction of tunable devices that react to environmental stimuli in programmable ways.

The authors highlighted some obstacles to the precise control of phonons at the nanoscale. For instance, the lack of standard transducers limits the ability to control interactions with other excitations, and high material quality is needed in high-frequency implementations.

Given the strong potential applications, the team is confident that researchers will address these challenges and continue to develop nanophononics as a valuable tool.

“The next steps include the design and realization of high-quality acoustic resonators operating at the ultrahigh-frequency range to provide a suitable platform to enter into the quantum regime at standard cryogenic temperatures,” said Lanzillotti-Kimura.

Source: “Perspectives on high-frequency nanomechanics, nanoacoustics, and nanophononics,” by Priya Priya, Edson Rafael Cardozo de Oliveira, and Norberto Daniel Lanzillotti-Kimura, Applied Physics Letters (2023). The article can be accessed at https://doi.org/10.1063/5.0142925.