Theory of high bias Coulomb Blockade in ultrashort molecules

Abstract

We point out that single electron charging effects such as Coulomb Blockade (CB) and high-bias staircases play a crucial role in transport through single ultrashort molecules. A treatment of Coulomb Blockade through a prototypical molecule, benzene, is developed using a master-equation in its complete many-electron Fock space, evaluated through exact diagonalization or full Configuration Interaction (CI). This approach can explain a whole class of non-trivial experimental features including vanishing zero bias conductances, sharp current onsets followed by ohmic current rises, and gateable current levels and conductance structures, most of which cannot be captured even qualitatively within the traditional Self Consistent Field (SCF) approach coupled with perturbative transport theories. By comparing the two approaches, namely SCF and CB, in the limit of weak coupling to the electrode, we establish that the inclusion of strong-correlations within the molecule becomes critical in addressing the above experiments. Our approach includes on-bridge-correlations fully, and is therefore well-suited for describing transport through short molecules in the limit of weak coupling to electrodes.

arXiv comment19 pages 5 figures

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Cited by in corpus (7)

• Molecular Transport Junctions: Vibrational Effects
• Negative differential resistance in nanoscale transport in the Coulomb blockade
• A multideterminant assessment of mean field methods for the description of electron transfer in the weak coupling regime
• Rectification by charging -- the physics of contact-induced current asymmetry in molecular conductors
• Negative Differential Conductance in Nano-junctions: A Current Constrained Approach
• Electron transfer through a single barrier inside a molecule: from strong to weak coupling
• Coupling optical and electrical gating for electronic read-out of quantum dot dynamics