Materials Research Lecture - Caltech Young Investigator Lecture Series
In nanoscale systems, in which the relevant length scales can be comparable to the mean free paths and wavelengths of the energy, charge, and spin carriers, it is necessary to examine the microscopic transport of heat, spin and charge at the atomic scale and the quantization of the associated quasiparticles. The intricacies of the transport dynamics can be even more complicated in materials with atomic scale complexities, such as incommensurate crystals, magnetic materials, and quasi-one- dimensional systems. Meanwhile, the transport properties and coupling between these quasiparticles are important in determining the strength of various thermoelectric and spincaloritronic phenomena, as well as the performance and reliability of nanoscale electronics. This talk will discuss the transport of heat in complex structured materials at nanometer and micrometer length scales, and address some of the fundamental questions about the interactions between energy, charge, and spin carriers in materials such as the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), the incommensurate thermoelectric material higher manganese silicide (HMS), and the magnetic insulator yttrium iron garnet (YIG). These questions are addressed with a number of experimental approaches using thermal conductance and thermoelectric property measurements of suspended nanostructures, inelastic neutron scattering, Brillouin light scattering, and electron microscopy.