The isostructural and isoelectronic transition-metal-dichalcogenides 1T-TaS2 and 1T-TaSe2 are layered materials with intricate electronic structures.Combining the molecular beam epitaxy growth,scanning tunneling micro...The isostructural and isoelectronic transition-metal-dichalcogenides 1T-TaS2 and 1T-TaSe2 are layered materials with intricate electronic structures.Combining the molecular beam epitaxy growth,scanning tunneling microscopy measurements and first-principles calculations,we prepare monolayer 1T-TaS2 and TaSe2 and explore their electronic structures at the atomic scale.Both two-dimensional(2D)compounds exhibit commensurate charge density wave phase at low temperature.The conductance mapping identifies the contributions from different Ta atoms to the local density of states with spatial and energy resolution.Both 1T-TaS2 and 1T-TaSe2 monolayer are shown to be insulators,while the former has a Mott gap and the latter is a regular band insulator.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11874233,11622433,and 11574175)the Ministry of Science and Technology of China(Nos.2016YFA0301002 and 2018YFA0305603).
文摘The isostructural and isoelectronic transition-metal-dichalcogenides 1T-TaS2 and 1T-TaSe2 are layered materials with intricate electronic structures.Combining the molecular beam epitaxy growth,scanning tunneling microscopy measurements and first-principles calculations,we prepare monolayer 1T-TaS2 and TaSe2 and explore their electronic structures at the atomic scale.Both two-dimensional(2D)compounds exhibit commensurate charge density wave phase at low temperature.The conductance mapping identifies the contributions from different Ta atoms to the local density of states with spatial and energy resolution.Both 1T-TaS2 and 1T-TaSe2 monolayer are shown to be insulators,while the former has a Mott gap and the latter is a regular band insulator.