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Title: Designing field-controllable graphene-dot-graphene single molecule switches: A quantum-theoretical proof-of-concept under realistic operating conditions

A theoretical proof of the concept that a particularly designed graphene-based moletronics device, constituted by two semi-infinite graphene subunits, acting as source and drain electrodes, and a central benzenoid ring rotator (a “quantum dot”), could act as a field-controllable molecular switch is outlined and analyzed with the density functional theory approach. Besides the ideal (0 K) case, we also consider the operation of such a device under realistic operating (i.e., finite-temperature) conditions. An in-depth insight into the physics behind device controllability by an external field was gained by thorough analyses of the torsional potential of the dot under various conditions (absence or presence of an external gating field with varying strength), computing the torsional correlation time and transition probabilities within the Bloembergen-Purcell-Pound formalism. Both classical and quantum mechanical tunneling contributions to the intramolecular rotation were considered in the model. The main idea that we put forward in the present study is that intramolecular rotors can be controlled by the gating field even in cases when these groups do not possess a permanent dipole moment (as in cases considered previously by us [I. Petreska et al., J. Chem. Phys. 134, 014708-1–014708-12 (2011)] and also by other groups [P. E. Kornilovitch etmore » al., Phys. Rev. B 66, 245413-1–245413-7 (2002)]). Consequently, one can control the molecular switching properties by an external electrostatic field utilizing even nonpolar intramolecular rotors (i.e., in a more general case than those considered so far). Molecular admittance of the currently considered graphene-based molecular switch under various conditions is analyzed employing non-equilibrium Green’s function formalism, as well as by analysis of frontier molecular orbitals’ behavior.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Department of Physical Chemistry, Institute of Chemistry, SS. Cyril and Methodius University, Arhimedova 5, P.O. Box 162, 1001 Skopje, Republic of Macedonia (Macedonia, The Former Yugoslav Republic of)
  2. Institute of Physics, Faculty of Natural Sciences and Mathematics, SS. Cyril and Methodius University, P.O. Box 162, 1001 Skopje, Republic of Macedonia (Macedonia, The Former Yugoslav Republic of)
  3. Macedonian Academy of Sciences and Arts, Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Republic of Macedonia (Macedonia, The Former Yugoslav Republic of)
  4. (Macedonia, The Former Yugoslav Republic of)
  5. (United States)
Publication Date:
OSTI Identifier:
22493427
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 24; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CONTROL; CORRELATIONS; DENSITY FUNCTIONAL METHOD; DIPOLE MOMENTS; ELECTRODES; EQUILIBRIUM; GAIN; GRAPHENE; MOLECULES; OPERATION; POTENTIALS; QUANTUM DOTS; QUANTUM MECHANICS; ROTATION; ROTORS; SWITCHES; TUNNEL EFFECT