The transition metal dichalcogenide TiSe2 has received significant research attention over the past four decades. Different studies have presented ways to suppress the 200~K charge density wave transition, vary low temperature resistivity by several orders of magnitude, and stabilize magnetism or superconductivity. Here we give the results of a new synthesis technique whereby samples were grown in a high pressure environment with up to 180~bar of argon gas. Above 100~K, properties are nearly unchanged from previous reports, but a hysteretic resistance region that begins around 80~K, accompanied by insulating low temperature behavior, is distinct from anything previously observed. An accompanying decrease in carrier concentration is seen in Hall effect measurements, and photoemission data show a removal of an electron pocket from the Fermi surface in an insulating sample. We conclude that high inert gas pressure synthesis accesses an underlying nonmetallic ground state in a material long speculated to be an excitonic insulator.
@article{arxiv.1809.09467,
title = {Intrinsic Insulating Ground State in Transition Metal Dichalcogenide TiSe2},
author = {Daniel J. Campbell and Chris Eckberg and Peter Y. Zavalij and Hsiang-Hsi Kung and Elia Razzoli and Matteo Michiardi and Chris Jozwiak and Aaron Bostwick and Eli Rotenberg and Andrea Damascelli and Johnpierre Paglione},
journal= {arXiv preprint arXiv:1809.09467},
year = {2019}
}