We employ a four-band continuum model to study the transport and confinement in an n-p-n junction in bilayer chiral borophene for both the identical- and oppositechirality configurations. The conditions for transport and confinement are elucidated in terms of the pseudospin. We study the transmission and reflection probabilities, conductances, and bound states. We demonstrate the existence of topological states in a domain wall between domains of opposite-chirality bilayer chiral borophene with reversed layer stacking. We find that changing the interlayer bias modifies the conductance of the identical-chirality configuration but not that of the opposite-chirality configuration, and that it induces a layer localization of the bound and topological states. Our findings suggest paths towards utilization of the layer degree of freedom in bilayer chiral borophene in future electronic devices.

Orientador: Prof. Dr. Gustavo Martini Dalpian / Coorientador: Prof. Dr. Adalberto Fazzio / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, Santo André, 2017.

Recent experimental advances for the fabrication of various borophene sheets introduced new structures with a wide range of applications. Borophene is the boron atom analogue of graphene. Borophene exhibits various structural polymorphs all of which are metallic. In this work, we employed first-principles density functional theory calculations to investigate the mechanical properties of five different single-layer borophene sheets. In particular, we analyzed the effect of the loading direction and point vacancy on the mechanical response of borophene. Moreover, we compared the thermal stabilities of the considered borophene systems. Based on the results of our modelling, borophene films depending on the atomic configurations and the loading direction can yield a remarkable elastic modulus in the range of 163–382 GPa nm and a high ultimate tensile strength from 13.5 GPa nm to around 22.8 GPa nm at the corresponding strain from 0.1 to 0.21. Our study reveals the remarkable mechanical characteristics of borophene films.