This symposium aims at addressing fundamental issues related to phonon transport, interactions and manipulation in both nanoscale and bulk materials with an eye towards phonon engineered materials and devices. Demands on engineered phonon properties are ever increasing for a wide range of devices and materials-based solutions. However, gaps between the fundamental understanding and technological demands still remain, particularly in our understanding of phonon interactions.
Due to the rapid progress on materials growth techniques, the list of available materials and the range of possibilities in growth control are expanding. While methods for the precise control of the electronic transport properties as well as for engineering electronic wave functions are presently available, less attention has been paid to the control of the degrees of freedom associated with the crystal lattice - the phonons. However, as the miniaturization of electronic devices progressed during the last decade, thermal management has become a substantial issue in the design of nanoscale electronic devices due to the rapid decrease in phonon transport lengths (and corresponding deterioration of the thermal conductivity) in nanoscale structure. Moreover, phonons play an active role in the functionality of other classes of devices including thermoelectrics, and thermal diodes. In fundamental research over the past few years significant progress has been made in our knowledge of phonon transport across and along arbitrary interfaces, scattering of phonons by crystal defects, delocalized electrons/collective electronic excitations, and solid acoustic vibrations when these occur in structures with small physical dimensions. Phonon interactions generally strongly depend on the length scale, and phonons in nanoscale material show complex behavior. The ensemble behavior of scale-dependent phonon interactions and disentanglement of the complex mechanisms determining the thermal properties of a variety of nanoscale materials are major focuses of the symposium. This includes experiments, and modeling of phonon interactions, transport, and manipulation in bulk and nanoscale materials, and devices.
In addition, novel concepts for phonon devices based on the phonon wave nature are presently emerging. Examples include the quantum control and transport of spins as well as the manipulation of quantum dots and of polariton condensates using phonons. At the same time, a number of novel techniques for the generation, detection, and manipulation of coherent phonons has been developed. Detection, modeling and manipulation of the coherent nature of the fundamental interactions between phonons and electrons, spins, excitons, and other elementary excitations is another thrust in this symposium. Closing these gaps between the fundamental understanding and demands on engineered phonon properties in materials will enable the design of structures that provide novel solutions and enhance our scientific knowledge of applications in areas including nano-photonics, plasmonics, photovoltaics, terahertz photonics, and nanomechanics, etc.