Molecular Beam Epitaxy of thin HfTe2 semimetal films

TL;DR

This study reports the successful epitaxial growth of thin HfTe2 semimetal films on AlN substrates using MBE, revealing their topological Dirac semimetal nature through combined experimental and theoretical analysis.

Contribution

First demonstration of epitaxial HfTe2 thin films with topological Dirac semimetal properties via MBE growth and combined spectroscopic and computational characterization.

Findings

HfTe2 films are unstrained and azimuthally aligned with AlN substrates.

Electronic structure shows linearly dispersing bands crossing near the zone center.

Evidence of topological Dirac semimetal behavior in epitaxial HfTe2 films.

Abstract

Epitaxial thin films of 1T-HfTe2 semimetal are grown by MBE on AlN(0001) substrates. The measured in-plane lattice parameter indicates an unstrained film which is also azimuthally aligned with the AlN substrate, albeit with an in-plane mosaic spread, as it would be expected for van der Waals epitaxy. Angle resolved photoemission spectroscopy combined with first principles electronic band structure calculations show steep linearly dispersing conduction and valence bands which cross near the Brillouin zone center, providing evidence that HfTe2 /AlN is an epitaxial topological Dirac semimetal.