Realization of metallic state in 1T-TaS2 with persisting long-range order of charge density wave

Abstract

Metallization of 1T-TaS2 is generally initiated at the domain boundary of charge density wave (CDW), at the expense of its long-range order. However, we demonstrate in this study that the metallization of 1T-TaS2 can be also realized without breaking the long-range CDW order upon surface alkali doping. By using scanning tunneling microscopy, we find the long-range CDW order is always persisting, and the metallization is instead associated with additional in-gap excitations. Interestingly, the in-gap excitation is near the top of the lower Hubbard band, in contrast to a conventional electron-doped Mott insulator where it is beneath the upper Hubbard band. In combination with the numerical calculations, we suggest that the appearance of the in-gap excitations near the lower Hubbard band is mainly due to the effectively reduced on-site Coulomb energy by the adsorbed alkali ions.

6 pages, 4 figures, to appear in Phys. Rev. Lett

References in corpus (4)

• Mott Physics and Topological Phase Transition in Correlated Dirac Fermions
• Gapless excitations in the ground state of 1T-TaS${}_2$
• The low-temperature highly correlated quantum phase in the charge-density-wave 1T-TaS_2 compound
• Heat transport study of the spin liquid candidate 1T-TaS2

Cited by in corpus (6)

• Direct identification of Mott Hubbard band pattern beyond charge density wave superlattice in monolayer 1T-NbSe2
• Evidence for a spinon Kondo effect in cobalt atoms on single-layer 1T-TaSe${}_2$
• Electron delocalization in a 2D Mott insulator
• Thickness dependent charge density wave networks on thin 1T-TaS${}_2$
• Transport and spectroscopic signatures of a disorder-stabilized metal in two-dimensional frustrated Mott insulators
• Scanning tunneling microscopy study of hidden phases in atomically thin 1T-TaS${}_2$