Distinguishing Lead and Molecule States in Graphene-Based Single-Electron Transistors
Author(s):
Pascal Gehring, Jakub K. Sowa, Jonathan Cremers, Qingqing Wu, Hatef Sadeghi, Yuewen Sheng, Jamie H. Warner, Colin J. Lambert, G. Andrew D. Briggs, Jan A. Mol
Journal:
ACS Nano
Year:
2017
Volume:
11
Pages
5325–5331
DOI:
10.1021/acsnano.7b00570
Abstract:
Graphene provides a two-dimensional platform for contacting individual molecules, which enables transport spectroscopy of molecular orbital, spin, and vibrational states. Here we report single-electron tunneling through a molecule that has been anchored to two graphene leads. Quantum interference within the graphene leads gives rise to an energy-dependent transmission and fluctuations in the sequential tunnel-rates. The lead states are electrostatically tuned by a global back-gate, resulting in a distinct pattern of varying intensity in the measured conductance maps. This pattern could potentially obscure transport features that are intrinsic to the molecule under investigation. Using ensemble averaged magneto-conductance measurements, lead and molecule states are disentangled, enabling spectroscopic investigation of the single molecule.