  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.

Materials Science