News Finding: [Contact: Dawn Levy, (865) 576-6448; levyd@ornl.gov]
  
  Image: https://www.ornl.gov/sites/default/files/2019-05/Materials-Engineering_heat_transport_0.png
  
  Caption: In a perfect thermoelectric crystal, vibrational waves decompose and localize.
Paper Finding: As is evident, increasing temperature shrinks the available phase space for scattering, which explains the anomalous sharpening of the LA linewidths.
News Context: The discovery improves understanding of thermoelectric performance and may enable unconventional heat transport in future materials. [Contact: Dawn Levy, (865) 576-6448; levyd@ornl.gov]
  
  Image: https://www.ornl.gov/sites/default/files/2019-05/Materials-Engineering_heat_transport_0.png
  
  Caption: In a perfect thermoelectric crystal, vibrational waves decompose and localize. A diagram of simulated phonon energy versus momentum reveals exactly where heat transport stops because of vibrations interfering nonlinearly--the flat band between the curved top and V-shaped bottom bands.
Paper Context: The phase space for this type of scattering is the surface shown in Fig. As is evident, increasing temperature shrinks the available phase space for scattering, which explains the anomalous sharpening of the LA linewidths. 1 ) suggests a transition in the anharmonic dynamics.