scholarly journals Quantum transport in a single molecular transistor at finite temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manasa Kalla ◽  
Narasimha Raju Chebrolu ◽  
Ashok Chatterjee
Keyword(s):  
Quantum Dot ◽  
Quantum Transport ◽  
Central Region ◽  
Finite Temperature ◽  
Tunneling Current ◽  
Differential Conductance ◽  
Function Technique ◽  
Quantum Dissipation ◽  
Electron Phonon Interaction ◽  
Molecular Transistor

AbstractWe study quantum transport in a single molecular transistor in which the central region consists of a single-level quantum dot and is connected to two metallic leads that act as a source and a drain respectively. The quantum dot is considered to be under the influence of electron–electron and electron–phonon interactions. The central region is placed on an insulating substrate that acts as a heat reservoir that interacts with the quantum dot phonon giving rise to a damping effect to the quantum dot. The electron–phonon interaction is decoupled by applying a canonical transformation and then the spectral density of the quantum dot is calculated from the resultant Hamiltonian by using Keldysh Green function technique. We also calculate the tunneling current density and differential conductance to study the effect of quantum dissipation, electron correlation and the lattice effects on quantum transport in a single molecular transistor at finite temperature.

scholarly journals Quantum Transport in A Single Molecular Transistor at Finite Temperature

2020 ◽  
Author(s):  
Manasa Kalla ◽  
Narasimha Raju Chebrolu ◽  
Ashok Chatterjee
Keyword(s):  
Quantum Dot ◽  
Quantum Transport ◽  
Central Region ◽  
Finite Temperature ◽  
Tunneling Current ◽  
Differential Conductance ◽  
Function Technique ◽  
Quantum Dissipation ◽  
Electron Phonon Interaction ◽  
Molecular Transistor

Abstract We study quantum transport in a single molecular transistor in which the central region consists of a single-level quantum dot and is connected to two metallic leads that act as a source and a drain respectively. The quantum dot is considered to be under the influence of electron-electron and electron-phonon interactions. The central region is placed on an insulating substrate that acts as a heat reservoir that interacts with the quantum dot phonon giving rise to a damping effect to the quantum dot. The electron-phonon interaction is decoupled by applying a canonical transformation and then the spectral density of the quantum dot is calculated from the resultant Hamiltonian by using Keldysh Green function technique. We also calculate the tunneling current density and differential conductance to study the effect of quantum dissipation, electron correlation and the lattice effects on quantum transport in a single molecular transistor at finite temperature.

scholarly journals Magneto-transport properties of a single molecular transistor in the presence of electron-electron and electron-phonon interactions and quantum dissipation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Manasa Kalla ◽  
Narasimha Raju Chebrolu ◽  
Ashok Chatterjee
Keyword(s):  
Transport Properties ◽  
Differential Conductance ◽  
Function Technique ◽  
Electron Interaction ◽  
Polarization Current ◽  
Quantum Dissipation ◽  
Electron Phonon Interaction ◽  
Spin Polarized ◽  
The Green Function ◽  
Molecular Transistor

Abstract A single molecular transistor is considered in the presence of electron-electron interaction, electron-phonon interaction, an external magnetic field and dissipation. The quantum transport properties of the system are investigated using the Anderson-Holstein Hamiltonian together with the Caldeira-Leggett model that takes care of the damping effect. The phonons are first removed from the theory by averaging the Hamiltonian with respect to a coherent phonon state and the resultant electronic Hamiltonian is finally solved with the help of the Green function technique due to Keldysh. The spectral function, spin-polarized current densities, differential conductance and spin polarization current are determined.

MESOSCOPIC TRANSPORT THROUGH A QUANTUM-DOT-EMBEDDED AHARONOV–BOHM RING THREADED WITH AC FLUX

2001 ◽  
Vol 15 (08) ◽  
pp. 1177-1192 ◽  
Author(s):  
HONG-KANG ZHAO
Keyword(s):  
Quantum Dot ◽  
Tunneling Current ◽  
Differential Conductance ◽  
Function Technique ◽  
Zero Temperature ◽  
Mesoscopic Transport ◽  
Conductance Oscillation ◽  
Nonequilibrium Green Function ◽  
Multi Level ◽  
Aharonov Bohm

The electron transporting through a mesoscopic ring embedded with one quantum dot and threaded by dc and ac magnetic fluxes is investigated by employing the Keldysh nonequilibrium Green function technique. The tunneling current and differential conductance are derived to show the Aharonov–Bohm-like effect induced by external magnetic fluxes. The multi-channel ring and multi-level quantum dot system is studied. The quenching and nonmonotone effects versus the magnitude of ac flux are revealed in differential conductance. This signifies that at some values of ac flux, the tunneling current may be suppressed or enhanced. The differential conductance oscillation and I-V characteristics are studied numerically at zero temperature. The aperiodically nonmonotonical conductance versus the magnitude of ac flux, multi-channel negative differential conductance, photon-electron pump effect are also observed.

MESOSCOPIC TRANSPORT THROUGH A QUANTUM DOT–CARBON NANOTUBE SYSTEM IN AN APPLIED MICROWAVE FIELD

2004 ◽  
Vol 18 (14) ◽  
pp. 2071-2084 ◽  
Author(s):  
LI-NA ZHAO ◽  
HONG-KANG ZHAO
Keyword(s):  
Quantum Dot ◽  
Microwave Field ◽  
Quantum Wires ◽  
Energy Levels ◽  
Tunneling Current ◽  
Differential Conductance ◽  
Single Wall Carbon Nanotubes ◽  
The Novel ◽  
Coherent Transport ◽  
Drain Bias

The coherent transport through a quantum-dot (QD) coupled with single-wall carbon nanotubes (SWCNs) is investigated by employing the nonequilibrium Green's function (NGF) technique. An external microwave field is applied to the central QD to induce side-bands in addition to the energy levels of the QD. The SWCNs act as quantum wires which open quantum channels for electron to transport through. The novel behaviors are obtained in differential conductance and tunneling current, which are strongly associated with the density of states (DOS) of leads. The hybrid system with a QD coupled to normal metal and SWCN is also investigated as a comparison. The armchair SWCN lead provides rich tunneling channels compared with that of a metal lead. The I–V characteristics is calculated to exhibit stair-like structures which correspond to the resonant peaks of differential conductance versus source–drain bias. The current resonance with the gate voltage is shown to exhibit the photon-assisted tunneling.

Quantum transport through quantum dot with electron-phonon interaction

2020 ◽  
Vol 39d (2) ◽  
pp. 176-180
Author(s):  
Manish Kumar Bhatt ◽  
Sanjiv Kumar ◽  
Sunil Kumar Mishra
Keyword(s):  
Quantum Dot ◽  
Quantum Transport ◽  
Phonon Interaction ◽  
Electron Phonon Interaction

scholarly journals Unidirectional quantum transport in optically driven V -type quantum dot chains

2021 ◽  
Vol 103 (11) ◽  
Author(s):  
Oliver Kaestle ◽  
Emil Vosmar Denning ◽  
Jesper Mørk ◽  
Andreas Knorr ◽  
Alexander Carmele
Keyword(s):  
Quantum Dot ◽  
Quantum Transport
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