Electronic transport in planar atomic-scale structures measured by two-probe scanning tunneling spectroscopy

ROM 2019-06
Author: Dr. Marek Kolmer (kolmerma@ornl.gov)
Institute: Jagiellonian University and Oak Ridge National Laboratory
Publication: Nature Comm 10, 1573 (2019) DOI: s41467-019-09315-6
Instrument: LT NANOPROBE

Miniaturization of electronic circuits into the single-atom level requires novel approaches to characterize transport properties. In this work, Kolmer et al. directly observe quasi-1D electronic transport channels provided by the unoccupied surface states running along the dimer rows on the Ge(001) surface. The authors introduce a method for the determination of the transconductance in a two-probe experimental setup and demonstrate how it captures energy-resolved information about electronic transport. The experiments are made using a two-probe scanning tunneling spectroscopy approach allowed by an atomically precise STM probe positioning protocol with relative probe-to-probe separation distances down to 30 nm. The sequential opening of two transport channels within the Ge dimer row gives rise to two distinct resonances in the transconductance spectroscopic signal. These experimental results are corroborated by first-principles multi-terminal transport calculations. The work paves the way to characterization of transport at the nanoscale in planar atomic-scale devices and 2D materials grown on surfaces.

Key Result:

Introduction of the two-probe scanning tunneling spectroscopy as a method for electronic transport characterization of atomic-scale systems supported on surfaces.


Marek Kolmer1,2, Pedro Brandimarte3, Jakub Lis1, Rafal Zuzak1, Szymon Godlewski1, Hiroyo Kawai4, Aran Garcia-Lekue3,5, Nicolas Lorente6, Thomas Frederiksen3,5, Christian Joachim7, Daniel Sanchez-Portal6 & Marek Szymonski1


1) Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, PL 30-348 Kraków, Poland.

2) Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.

3) Donostia International Physics Center, DIPC, Paseo Manuel de Lardizabal 4, E-20018 Donostia-San Sebastián, Spain.

4) Institute of Materials Research and Engineering, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore.

5) IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao, Spain.

6) Center for Materials Physics CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, E-20018 Donostia-San Sebastián, Spain.

7) Nanoscience Group & MANA Satellite, CEMES/CNRS, 29 rue Marvig, BP 94347, 31055 Toulouse, France.