Title: Electron localization in disordered quantum systems at finite temperatures

Abstract: We study electron localization in disordered quantum systems, focusing on both individual eigenstates and thermal states. We employ complex polarization as a numerical indicator to characterize the system's localization length. Furthermore, we assess the efficacy of mean-field approximation in providing a quantitative analysis of such systems. Through this study, we seek to provide insight into the following aspects: the behavior of electron localization as a function of interaction, disorder, and temperature, whether thermal states and highly excited states exhibit similar properties in many-body localized systems, and the reliability of the mean-field approximation in low-interaction scenarios.