Mott phase at the surface of 1T-TaSe2 observed by scanning tunneling microscopy

Phys Rev Lett. 2005 Jan 28;94(3):036405. doi: 10.1103/PhysRevLett.94.036405. Epub 2005 Jan 25.

Abstract

In this Letter we report the observation, by scanning tunneling microscopy, of a Mott metal to insulator transition at the surface of 1T-TaSe2. Our spectroscopic data compare considerably well with previous angle-resolved photoemission spectroscopy measurements and confirm the presence of a large hysteresis related to a first order process. The local character of the tunneling spectroscopy technique allows a direct visualization of the surface symmetry and provides spectroscopic measurements on the defect-free region of the sample. It follows that the electronic localization is driven purely by the enhancement of the charge density wave amplitude which drives a bandwidth controlled metal-insulator transition.