A novel $\sqrt{19}\times \sqrt{19}$ superstructure in epitaxially grown 1T-TaTe${}_2$

Abstract

The spontaneous formation of electronic orders is a crucial element for understanding complex quantum states and engineering heterostructures in two-dimensional materials. We report a novel $\sqrt{19}\times \sqrt{19}$ charge order in few-layer thick 1T-TaTe${}_2$ transition metal dichalcogenide films grown by molecular beam epitaxy, which has not been realized. Our photoemission and scanning probe measurements demonstrate that monolayer 1T-TaTe${}_2$ exhibits a variety of metastable charge density wave orders, including the $\sqrt{19}\times \sqrt{19}$ superstructure, which can be selectively stabilized by controlling the post-growth annealing temperature. Moreover, we find that only the $\sqrt{19}\times \sqrt{19}$ order persists in 1T-TaTe${}_2$ films thicker than a monolayer, up to 8 layers. Our findings identify the previously unrealized novel electronic order in a much-studied transition metal dichalcogenide and provide a viable route to control it within the epitaxial growth process.

References in corpus (9)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Fermi surface nesting and the origin of Charge Density Waves in metals
• Classification of Charge Density Waves Based on Their Nature
• Band insulator to Mott insulator transition in 1T-TaS${}_2$
• Intrinsic 2D Ferromagnetism in V5Se8 Epitaxial Thin Films
• Monolayer VTe2: Incommensurate Fermi surface nesting and suppression of charge density waves
• Switching of band inversion and topological surface states by charge density wave
• Large-gap insulating dimer ground state in monolayer IrTe2
• Electronic states of multilayer VTe2: quasi-one-dimensional Fermi surface and implications to charge-density waves

Cited by in corpus (1)

• Realization of multiple charge density waves in NbTe2 at the monolayer limit