Heat transport is driven by a thermal gradient, flowing from hot to cold regions in a material. However, at dimensions <100nm, bulk models no longer accurately predict the transport properties of materials. Because no complete models of nanoscale heat transport were available, it was assumed instead that bulk-like diffusive heat transport was valid—provided that an effective parameter, such as a size-dependent thermal conductivity, was incorporated.
Although x-ray imaging has been explored for decades, and visible-wavelength microscopy for centuries, it is only recently that the spectral region in between―the extreme ultraviolet (EUV)―has been explored for imaging nanostructures and nanomaterials.
Ever since the invention of the visible laser over 50 years ago, scientists have been striving to create lasers that generate coherent beams at shorter wavelengths i.e. the extreme UV (EUV) and soft X-ray (SXR) regions of the spectrum. This quest has led to the construction of large facilities, such as kilometer-scale x-ray free-electron lasers, to reach the keV photon energy region.
Physics Frontiers Centers (PFCs)
The Physics Frontiers Centers (PFC) program supports university-based centers and institutes where the collective efforts of a larger group of individuals can enable transformational advances in the most promising research areas. The program is designed to foster major breakthroughs at the intellectual frontiers of physics by providing needed resources such as combinations of talents, skills, disciplines, and/or specialized infrastructure, not usually available to individual investigators or small groups, in an environment in which the collective efforts of the larger group can be shown to be seminal to promoting significant progress in the science and the education of students. PFCs also include creative, substantive activities aimed at enhancing education, broadening participation of traditionally underrepresented groups, and outreach to the scientific community and general public. Read more about this program at the NSF website.
