K. Mohseni

Reversible Formation of 2D Electron Gas at the LaFeO3/SrTiO3 Interface via Control of Oxygen Vacancies

A conducting 2D electron gas (2DEG) is formed at the interface between epitaxial LaFeO3 layers >3 unit cells thick and the surface of SrTiO3 single crystals. The 2DEG is exquisitely sensitive to cation intermixing and oxygen nonstoichiometry. It is shown that the latter thus allows the controllable formation of the 2DEG via ionic liquid gating, thereby forming a nonvolatile switch.

Instability of the topological surface state in Bi 2 Se 3 upon deposition of gold

Momentum-resolved photoemission spectroscopy indicates the instability of the Dirac surface state upon deposition of gold on the (0001) surface of the topological insulator Bi2Se3. Based on the str ...

The Kepler tiling as the oldest complex surface structure in history: X-ray structure analysis of a two-dimensional oxide quasicrystal approximant

Abstract: We have carried out a surface X-ray diffraction (SXRD) analysis of the approximant structure related to the recently discovered two-dimensional dodecagonal oxidic quasicrystal. The structure is characterized by the 32.4.3.4 Archimedean tiling, first described by Kepler in 1619. The tiling network is related to titanium atoms observed as protrusions in scanning tunneling microscopy images. All four titanium atoms within one two-dimensional unit cell (a0=13.1 Å, b0=12.9 Å, γ=90.5°) are surrounded by three oxygen atoms. The TiO3 units are separated by barium atoms. The total stoichiometry is given by Ba4 Ti4 O10.