Quantifying non-Gaussian diffusion in transient microscopy using excess kurtosis

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Rodríguez, Enrique Arévalo, Schofield, Marc Meléndez, Cuadra, Jorge, Prins, Ferry
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866914202353926144
author Rodríguez, Enrique Arévalo
Schofield, Marc Meléndez
Cuadra, Jorge
Prins, Ferry
author_facet Rodríguez, Enrique Arévalo
Schofield, Marc Meléndez
Cuadra, Jorge
Prins, Ferry
contents Research on energy transport has advanced in recent years with the emergence of transient microscopy techniques that allow for imaging of carriers with high spatial and temporal resolution. In this context, transient scattering microscopy (TScM), has emerged as an alternative to traditional techniques. However, the sensitivity of TScM to different carriers can complicate the interpretation of results, highlighting the need to develop models tailored to TScM. Here, TScM is used to visualize exciton transport in bulk TMDCs. We show that exciton populations exhibit non-Gaussian profiles by analyzing the their excess kurtosis. Numerical simulations incorporating anomalous diffusion -- such as Auger recombination and trap states -- reproduce these experimental observations. Furthermore, by tuning the injected carrier density, we demonstrate that the temporal signature of the kurtosis is distinct for Auger-dominated and trap-dominated regimes. Additionally, we find that traditional Gaussian-fitting methods can yield inconsistent results for the extracted diffusivities. As an alternative, we implement a discrete variable calculation which yields robust, consistent diffusivity values. Our results establish kurtosis as a vital diagnostic parameter for identifying anomolous diffusion and demonstrate the necessity of moving beyond Gaussian approximations for accurate analysis of TScM data.
format Preprint
id arxiv_https___arxiv_org_abs_2510_15587
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quantifying non-Gaussian diffusion in transient microscopy using excess kurtosis
Rodríguez, Enrique Arévalo
Schofield, Marc Meléndez
Cuadra, Jorge
Prins, Ferry
Materials Science
Research on energy transport has advanced in recent years with the emergence of transient microscopy techniques that allow for imaging of carriers with high spatial and temporal resolution. In this context, transient scattering microscopy (TScM), has emerged as an alternative to traditional techniques. However, the sensitivity of TScM to different carriers can complicate the interpretation of results, highlighting the need to develop models tailored to TScM. Here, TScM is used to visualize exciton transport in bulk TMDCs. We show that exciton populations exhibit non-Gaussian profiles by analyzing the their excess kurtosis. Numerical simulations incorporating anomalous diffusion -- such as Auger recombination and trap states -- reproduce these experimental observations. Furthermore, by tuning the injected carrier density, we demonstrate that the temporal signature of the kurtosis is distinct for Auger-dominated and trap-dominated regimes. Additionally, we find that traditional Gaussian-fitting methods can yield inconsistent results for the extracted diffusivities. As an alternative, we implement a discrete variable calculation which yields robust, consistent diffusivity values. Our results establish kurtosis as a vital diagnostic parameter for identifying anomolous diffusion and demonstrate the necessity of moving beyond Gaussian approximations for accurate analysis of TScM data.
title Quantifying non-Gaussian diffusion in transient microscopy using excess kurtosis
topic Materials Science
url https://arxiv.org/abs/2510.15587