  Discovering new materials with ultrahigh thermal conductivity has been a
critical research frontier and driven by many important technological
applications ranging from thermal management to energy science. Here we have
rigorously investigated the fundamental lattice vibrational spectra in ternary
compounds and determined the thermal conductivity using a predictive ab initio
approach. Phonon transport in B-X-C (X = N, P, As) groups is systematically
quantified with different crystal structures and high-order anharmonicity
involving a four-phonon process. Our calculation found an ultrahigh
room-temperature thermal conductivity through strong carbon-carbon bonding up
to 2100 W/mK beyond most common materials and the recently discovered boron
arsenide. This study provides fundamental insight into the atomistic design of
thermal conductivity and opens up opportunities in new materials searching
towards complicated compound structures.
  DOI: 10.1103/PhysRevB.103.L041203
