Department of Physics
Permanent URI for this collectionhttp://localhost:4000/handle/123456789/1932
Browse
2 results
Search Results
Item MsSpec-DFM (Dielectric function module): Towards a multiple scattering approach to plasmon description(ARXIV, 2022-07) Choubisa, RakeshWe present here the MsSpec Dielectric Function module (MsSpec-DFM), which generates dielectric functions in an electron gas or a liquid, either isolated or embedded into an environment. In addition to standard models such as the plasmon pole and the RPA, this module also provides more involved methods incorporating local field corrections (in order to account for correlations), Boltzmann-Vlasov hydrodynamical methods, the relaxation-damped Mermin and the diffusion-damped Hu-O'Connell methods, as well as moment-based methods using either a Nevanlinna function or a memory function. Ultimately, through the use of form factors, the MsSpec-DFM module will be able to address a wide range of materials such as metals, semiconductors, including inversion layers, hetero-structures, superconductors, quantum wells, quantum wires, quantum dots, Dirac materials such as graphene, and liquids.Item Model dielectric functions for fluctuation potential calculations in electron gas: A critical assessment(APS, 2022-05) Choubisa, RakeshIn this article, we report on a critical assessment of dielectric function calculations in electron gas through the comparison of different modeling methods. This work is motivated by the fact that the dielectric function is a key quantity in the multiple scattering description of plasmon features in various electron-based spectroscopies. Starting from the standard random phase approximation (RPA) expression, we move on to correlation-augmented RPA, then damped RPA models. Finally, we study the reconstruction of the dielectric function from its moments, using the Nevanlinna and memory function approaches. We find the memory function method to be the most effective, being highly flexible and customizable.