Published April 28, 2023 | Version v1
Dataset Open

Polaron hopping through piecewise-linear functionals

  • 1. Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

* Contact person

Description

We use piecewise-linear functionals to study the polaron energy landscape and hopping rates in 𝜷-Ga₂O₃, which we adopt as an example of an anisotropic material hosting multiple polaronic states. We illustrate various functionals for polaron localization, including a hybrid functional and two types of semilocal functionals, and discuss how to ensure the piecewise linearity condition. Then, we determine the formation energies of stable polarons, and show that single-site and multi-site polaronic states can be found in close energetic competition. We calculate the hyperfine and superhyperfine parameters associated with each polaron, and discuss the comparison with experiment. Next, we perform nudged-elastic-band calculations to determine energy landscapes and hole transfer rates of all first-nearest-neighbor polaron hoppings. We show that when the piecewise linearity condition is ensured polaron properties are robust upon variation of the functional adopted, including formation energies, energy barriers, and charge transfer rates. This supports the use of semilocal functionals for calculating polaron transport properties.

Files

File preview

files_description.md

All files

Files (1020.7 KiB)

Name Size
md5:5ee7772e880871389b5c4e090bb003df
337 Bytes Preview Download
md5:10fc97e8f22123e160f4f3bc231a61a5
890.7 KiB Preview Download
md5:e7fb2d4c5e85bfd4bb403e0ff9d57ff4
7.1 KiB Download
md5:9eff93eef0dba3692add34ff11b1f573
122.6 KiB Preview Download

References

Journal reference (Paper in which the method is described)
S. Falletta, A. Pasquarello, Phys Rev B