Intrinsic Lattice Thermal Conductivity of Nanostructured Semiconductor Systems David Broido, Physics Dept. Boston College PRF# 44036-AC10 We have developed a theoretical description of phonon thermal transport and intrinsic lattice thermal conductivity in single-walled carbon nanotubes (SWCNTs). Our approach uses for the first time the correct selection rules that severely restrict the phonon-phonon scattering. We show that scattering of acoustic phonons by optic phonons is required to produce thermal resistance in SWCNTs. Phonon dispersion for (10,0) SWCNT. Solid thin lines indicate allowed normal and umklapp transitions. Dashed line shows umklapp transition between acoustic phonons that is symmetry-forbidden and cannot occur. See Physical Review B 80, 125407 (2009).