Impact of topological band inversion on Auger–Meitner recombination in rocksalt SnSe

Topological crystalline insulators, such as rocksalt SnSe, exhibit complicated electronic structure with inverted band topology. While the electronic structure of these materials is well captured by first-principles calculations, the carrier dynamics that critically impact application in devices remain poorly understood. As an important energy loss channel in narrow-gap materials, the Auger-Meitner recombination (AMR) process plays a key role in topological crystalline insulators. Unfortunately, calculations are computationally prohibitive due to the fine grids required to sample the complex electronic structure. To overcome this challenge, we have developed a highly efficient Monte Carlo importance sampling method based on a Uniformly Minimum Variance Unbiased Estimator (UMVUE) that leverages the natural sparsity of the AMR scattering phase space. With our newly developed approach, we rigorously investigate the influence of topological phase transitions on the AMR rates in SnSe. We demonstrate a correlation between the AMR coefficient and band structure inversion, providing crucial insights into the carrier dynamics in topological materials.