Disordered Mott-Hubbard Physics in Nanoparticle Solids: Transitions Driven by Disorder, Interactions, and Their Interplay

Nano Lett. 2020 Dec 9;20(12):8569-8575. doi: 10.1021/acs.nanolett.0c03141. Epub 2020 Nov 18.

Abstract

We show that adapting the knowledge developed for the disordered Mott-Hubbard model to nanoparticle (NP) solids can deliver many very helpful new insights. We developed a hierarchical nanoparticle transport simulator (HINTS), which builds from localized states to describe the disorder-localized and Mott-localized phases of NP solids and the transitions out of these localized phases. We also studied the interplay between correlations and disorder in the corresponding multiorbital Hubbard model at and away from integer filling by dynamical mean field theory. This DMFT approach is complementary to HINTS, as it builds from the metallic phase of the NP solid. The mobility scenarios produced by the two methods are strikingly similar and account for the mobilities measured in NP solids. We conclude this work by constructing the comprehensive phase diagram of PbSe NP solids on the disorder-filling plane.

Keywords: Coulomb blockade; Hubbard model; Monte Carlo; dynamical mean field theory; metal−insulator transition; nanoparticles.