# Shape effect on the valley splitting in lead selenide nanowires

## TL;DR

This study investigates how the cross-section shape and size of PbSe nanowires influence valley splitting energies, revealing significant shape-dependent variations with potential implications for nanowire electronic properties.

## Contribution

It provides a detailed analysis of shape and size effects on valley splitting in PbSe nanowires using empirical tight-binding calculations, highlighting the impact of cross-section geometry.

## Key findings

- Rectangular nanowires exhibit valley splitting up to hundreds of meV.
- Rhombic nanowires show almost no valley splitting.
- Shape dependence persists across various sizes and symmetries.

## Abstract

We study the cross-section shape and size effects on the valley splitting in PbSe nanowires within the framework of empirical $sp^3d^5s^*$ tight-binding method. We consider ideallized prismatic nanowires, grown along [110], with the cross-section shape varying from rectangular (terminated by $\{001\}$ and $\{110\}$ facets) to rhombic (terminated mostly by $\{111\}$ facets). The valley splitting energies have the maximal value (up to hundreds meV) in rectangular nanowires, while in rhombic ones they are almost absent. The shape dependence is shown to be similar for a wide range cross-section sizes and different point symmetries of nanowires.