Abstract
Phonon lifetimes are a key component of quasiparticle theories of transport; yet first-principles lifetimes are rarely directly compared with inelastic neutron scattering (INS) results. Existing comparisons show discrepancies even at temperatures where perturbation theory is expected to be reliable. In this paper, we demonstrate that the reciprocal space voxel (q voxel), which is the finite region in reciprocal space required in INS data analysis, must be explicitly accounted for within theory in order to draw a meaningful comparison. We demonstrate accurate predictions of peak widths of the scattering function when accounting for the q voxel in CaF2 and ThO2. Passing this test implies high fidelity of the phonon interactions and the approximations used to compute the Green's function, serving as a critical benchmark of theory and indicating that other material properties should be accurately predicted, which we demonstrate for thermal conductivity.
| Original language | English |
|---|---|
| Article number | 144310 |
| Journal | Physical Review B |
| Volume | 106 |
| Issue number | 14 |
| DOIs | |
| State | Published - Oct 1 2022 |
Funding
INS measurements, first-principles calculations, crystal growth, and thermal conductivity measurements were supported by the Center for Thermal Energy Transport under Irradiation, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE) Office of Science, Office of Basic Energy Sciences. Neutron scattering data acquisition and provision of were supported by the U.S. DOE Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. Portions of this research used resources at the Spallation Neutron Source, a U.S. DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The formulation and encoding of linewidths via irreducible derivatives was supported by Grant No. DE-SC0016507 funded by the U.S. Department of Energy, Office of Science. ORNL is managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy. The U.S. Government retains, and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes.
| Funders | Funder number |
|---|---|
| Center for Thermal Energy Transport | |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | DE-AC05-00OR22725 |
| Division of Materials Sciences and Engineering | DE-SC0016507, DE-AC02-05CH11231 |