Intrinsic insulating ground state in transition metal dichalcogenide
Physical Review Materials, 2019•APS
The transition metal dichalcogenide TiSe 2 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 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 distinct …
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 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 distinct …
The transition metal dichalcogenide 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 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 distinct hysteretic resistance region begins around 80 K, accompanied by insulating low-temperature behavior. 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.
American Physical Society