Coulomb gap triptych in a periodic array of metal nanocrystals

TL;DR

This paper discovers a novel 'Coulomb gap triptych' structure in the density of states of metallic nanocrystal arrays, revealing unique electronic properties and fixed gap widths, with implications for tunneling experiments.

Contribution

It introduces the concept of a Coulomb gap triptych in nanocrystal arrays and provides computational analysis of its properties, differing from traditional Coulomb glass models.

Findings

Identification of three identical Coulomb gaps forming a triptych structure

DOS has a fixed width in large disorder limit

Potential for experimental observation via tunneling

Abstract

The Coulomb gap in the single particle density of states (DOS) is a universal consequence of electron-electron interaction in disordered systems with localized electron states. Here we show that in arrays of monodisperse metallic nanocrystals, there is not one but three identical adjacent Coulomb gaps, which together form a structure that we call a "Coulomb gap triptych." We calculate the DOS and the conductivity in two- and three-dimensional arrays using a computer simulation. Unlike in the conventional Coulomb glass models, in nanocrystal arrays the DOS has a fixed width in the limit of large disorder. The Coulomb gap triptych can be studied via tunneling experiments.