Effect of Inter-dot Coupling on Transmission Probability of a Triple Quantum Dot Systems

S. Chand¹ , S. Devi²

Section:Research Paper, Product Type: Journal-Paper
Vol.9 , Issue.3 , pp.15-20, Jun-2021

Online published on Jun 30, 2021

Copyright © S. Chand, S. Devi . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
 

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Abstract :
Following the techniques of non-equilibrium Green function theory for quantum transport, the transmission probability for the electron transport process through the system of linear triple quantum dots arranged in series and parallel geometry has been investigated in the presence of Coulombic interaction. The mean field approximation technique has been applied to decouple the higher order Green functions, which contain Coulomb interaction in their equations of motion. The Green functions so obtained have been incorporated in the derivations for the electron transmission coefficient. The transmission coefficient has been calculated numerically and the role of inter-dot tunneling rate in the behavior of transmission coefficient has been investigated. In series case, the signatures of merging of three dots to form a single big dot become visible in the transmission peak when inter-dot tunneling exceeds lead-dot coupling strength. Whereas, in the parallel configuration, the transmission probability peaks display the clear signs of Fano peaks when inter-dot tunneling is turned on, which indicates the inter-dot tunneling induced Fano interference occurring during the electron transport.

Key-Words / Index Term :
Coulomb Blockade Regime, Quantum Dot, Triple Quantum Dot System, Transmission Probability, Fano Effect

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