Generating Weyl semimetals from alkali metals

TL;DR

This paper demonstrates how to create a Weyl semimetal with topologically protected surface states by modifying a model of alkali metals, revealing a new pathway for designing materials with Weyl fermions.

Contribution

It introduces a method to generate Weyl semimetals from conventional alkali metals through Hamiltonian modification, bridging simple metals and topological phases.

Findings

Identified four Weyl nodes in the modified alkali metal model.

Observed characteristic surface Fermi arcs.

Weyl semimetal appears between insulator and topological insulator phases.

Abstract

We report the discovery of a time-reversal symmetric Weyl semimetal obtained by modifying a model Hamiltonian describing the electronic properties of conventional alkali metals. The artificially generated Weyl semimetal features four isolated Weyl nodes in its bulk band structure and displays characteristic surface Fermi arcs arising from topologically protected surface states. The Weyl semimetal occurs as an intermediate state between a conventional band insulator and a three-dimensional topological insulator. The generation of topological Weyl semimetals from conventional metals opens a new route towards the deterministic design of simple materials hosting Weyl fermions.