Finite size and volume effects in line node semimetals: a first-principles investigation

TL;DR

This study uses first-principles calculations to explore how finite size, volume changes, and external pressure influence the electronic properties of line node semimetals, revealing ways to tune their surface states.

Contribution

It demonstrates the impact of slab thickness and volume variation on line node semimetals and proposes pressure or substrate engineering as tuning methods.

Findings

Ultra thin slabs are gapped, with line node signatures appearing beyond a critical thickness.

Line node radius is sensitive to bulk volume changes.

Pressure or substrate engineering can tune the line node and surface states.

Abstract

We systematically study the bulk and finite size effects on the band structure of prototypical line node materials using density functional theory based computations. For the bulk system, we analyze quantum oscillations with changes in the Fermi surface topology. We show that ultra thin slabs are gapped, with the first signatures of the line node appearing beyond a critical thickness. Further, motivated by possibility of tuning the bulk line node, we find that the line node radius is rather sensitive to bulk volume change. Based on this observation, we propose that application of pressure or suitable substrate engineering can be used as an effective means to control and tune the line node and the accompanying surface drumhead states.