Atomically precise lateral modulation of a two-dimensional electron liquid in anatase TiO2 thin films

Abstract

Engineering the electronic band structure of two-dimensional electron liquids (2DELs) confined at the surface or interface of transition metal oxides is key to unlocking their full potential. Here we describe a new approach to tailoring the electronic structure of an oxide surface 2DEL demonstrating the lateral modulation of electronic states with atomic scale precision on an unprecedented length scale comparable to the Fermi wavelength. To this end, we use pulsed laser deposition to grow anatase TiO2 films terminated by a (1 x 4) in-plane surface reconstruction. Employing photo-stimulated chemical surface doping we induce 2DELs with tunable carrier densities that are confined within a few TiO2 layers below the surface. Subsequent in-situ angle resolved photoemission experiments demonstrate that the (1 x 4) surface reconstruction provides a periodic lateral perturbation of the electron liquid. This causes strong backfolding of the electronic bands, opening of unidirectional gaps and a saddle point singularity in the density of states near the chemical potential.

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Cited by in corpus (8)

• Band Structure and Spin-Orbital Texture of the (111)-KTaO3 Two-Dimensional Electron Gas
• Selective control of localised vs. delocalised carriers in anatase TiO2 through reaction with O2
• Observation of a two-dimensional electron gas at CaTiO${}_3$ film surfaces
• Anisotropic Electronic Structure of the Two-Dimensional Electron Gas at the AlOx/KTaO3(110) interface
• Artificial quantum confinement in LAO3/STO heterostructure
• Soft x-ray irradiation induced metallization of layered TiNCl
• A Laser-ARPES View of the 2D Electron Systems at LaAlO3/SrTiO3 and Al/SrTiO3 Interfaces
• Electronic phase diagram of Cr-doped VO2 epitaxial films studied by in situ photoemission spectroscopy