Tunable Line Node Semimetals

TL;DR

This paper explores tunable line node semimetals, demonstrating how magnetization controls their nodal line properties and affects conductivity, with potential experimental signatures in quantum oscillations.

Contribution

It introduces a model for tunable line node semimetals using layered heterostructures and analyzes how magnetization influences their electronic structure and observable properties.

Findings

Nodal lines' shape and dispersion depend on magnetization strength.

Conductivity varies with magnetization, showing tunable electronic properties.

Quantum oscillation signatures reveal low energy sector characteristics.

Abstract

Weyl semimetals are examples of a new class of topological states of matter which are gapless in the bulk with protected surface states. Their low energy sector is characterized by massless chiral fermions which are robust against translationally invariant perturbations. A variant of these systems have two non-degenerate bands touching along lines rather than points. A proposal to realize such a phase involves alternating layers of topological insulators and magnetic insulators, where the magnetization lies perpendicular to the symmetry axis of the heterostructure. The shape, size and the dispersion in the vicinity of the nodal lines varies with the strength of the magnetization, offering a new knob to control the properties of the system. In this paper we map out the evolution of the nodal lines and the dependence of the conductivity on magnetization and identify signatures of the low energy sector in quantum oscillation measurements.