Kinkless electronic junction along one dimensional electronic channel

TL;DR

This paper reports the discovery of kinkless electronic junctions in a 1D electronic channel within a van der Waals layer, formed by interlayer coupling without structural discontinuities, studied via microscopy and density-functional calculations.

Contribution

It reveals a novel mechanism of electronic junction formation driven by interlayer coupling in 2D materials, without structural kinks or defects.

Findings

Distinct electronic junctions with band gap discontinuities along domain walls

Junctions formed by kinked domain walls in underlying layers

Interlayer electronic coupling controls nanoscale electronic properties

Abstract

Here we report the formation of type-A and type-B electronic junctions without any structural discontinuity along a well-defined 1-nm-wide one-dimensional electronic channel within a van der Waals layer. We employ scanning tunneling microscopy and spectroscopy techniques to investigate the atomic and electronic structure along peculiar domain walls formed on the charge-density-wave phase of 1T-TaS2. We find distinct kinds of abrupt electronic junctions with discontinuities of the band gap along the domain walls, which do not have any structural kinks and defects. Our density-functional calculations reveal a novel mechanism of the electronic junction formation; they are formed by a kinked domain wall in the layer underneath through substantial electronic interlayer coupling. This work demonstrates that the interlayer electronic coupling can be an effective control knob over several-nanometer-scale electronic property of two-dimensional atomic monolayers.