Electronic and magneto-optical properties of monolayer phosphorene quantum dots

TL;DR

This paper provides a theoretical analysis of the electronic and magneto-optical properties of variously shaped monolayer phosphorene quantum dots, revealing edge states, Hofstadter-butterfly spectra, and tunable properties.

Contribution

It introduces a comprehensive theoretical study of MPQDs, highlighting shape-dependent edge states and magnetic spectra, which were not previously detailed.

Findings

Edge states appear in the band gap regardless of shape and edge configuration.

Magnetic levels exhibit Hofstadter-butterfly spectrum and approach Landau levels with increasing magnetic field.

Electronic and optical properties are tunable by size, edge type, and magnetic field.

Abstract

We theoretically investigate the electronic and magneto-optical properties of rectangular, hexangular, and triangular monolayer phosphorene quantum dots (MPQDs) utilizing the tight-binding method. The electronic states, density of states, electronic density distribution, and Laudau levels as well as the optical absorption spectrum are calculated numerically. Our calculations show that: (1) edge states appear in the band gap in all kinds of MPQDs regardless of their shapes and edge configurations due to the anisotropic electron hopping in monolayer phosphorene (MLP). Electrons in any edge state appear only in the armchair direction of the dot boundary, which is distinct from that in graphene quantum dots; (2) the magnetic levels of MPQDs exhibit a Hofstadter-butterfly spectrum and approach the Landau levels of MLP as the magnetic field increases . A "flat band" appears in the magneto-energy spectrum which is totally different from that of MLP; (3) the electronic and optical properties can be tuned by the dot size, the types of boundary edges and the external magnetic field.