Zero bias maximum of differential conductance in coupled quantum dots: The effect of interdot Coulomb interaction

Rajput, Gagan; Chand, Shyam; Ahluwalia, P. K.; Sharma, K. C.

doi:10.1016/j.physb.2010.07.035

Cited by 11 publications

(7 citation statements)

References 28 publications

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“…Fano effect, a nice illustration of quantum interference phenomena has been explored for varied configuration under transition from series to symmetric parallel configuration by Ladron de Guevara [7], Feng Chi [3] etc. For similar transition Fano effect without flux [5,6] and with flux [12,13] has also been reported.…”

Section: Introductionsupporting

confidence: 73%

“…Research in this field remained focused on generic coupled quantum dot (CQD) system in which two or more quantum dots can be coupled in the form of artificial molecule. The CQD system offers very rich transport phenomena which can be investigated for series [1,2], parallel [3,4] and for asymmetric transition of the CQD system from series to parallel configuration [3,[5][6][7]. Theoretical and experimental work on the electron transport through this system for varied configuration has revealed various effects such as Kondo effect [8,9], interference effect [10] and Coulomb blockade effect [11].…”

Section: Introductionmentioning

confidence: 99%

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Fano effect dominance over Coulomb blockade in transport properties of parallel coupled quantum dot system

Brogi

Chand²,

Ahluwalia

2015

AIP Conference Proceedings

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Theoretical study of the Coulomb blockade effect on transport properties (Transmission Probability and I-V characteristics) for varied configuration of coupled quantum dot system has been studied by using Non Equilibrium Green Function(NEGF) formalism and Equation of Motion(EOM) method in the presence of magnetic flux. The self consistent approach and intra-dot Coulomb interaction is being taken into account. As the key parameters of the coupled quantum dot system such as dot-lead coupling, inter-dot tunneling and magnetic flux threading through the system can be tuned, the effect of asymmetry parameter and magnetic flux on this tuning is being explored in Coulomb blockade regime. The presence of the Coulomb blockade due to on-dot Coulomb interaction decreases the width of transmission peak at energy level + and by adjusting the magnetic flux the swapping effect in the Fano peaks in asymmetric and symmetric parallel configuration sustains despite strong Coulomb blockade effect.

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Section: Introductionsupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Fano effect dominance over Coulomb blockade in transport properties of parallel coupled quantum dot system

Brogi

Chand²,

Ahluwalia

2015

AIP Conference Proceedings

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“…However, the role of interdot Coulomb interactions on the formation of BICs and on swapping has not yet been thoroughly understood in the CB regime, particularly, in the simplest non-magnetic case. This issue has been addressed in the present work with some novel findings in respect of partial swapping and formation of BICs, within the framework of a generic approach developed earlier [18] for understanding the zero-bias maximum (ZBM) of differential conductance using the Keldysh non-equilibrium Green function technique [19]. We restrict ourselves to the parameter domain used in refs.…”

mentioning

confidence: 99%

Partial swapping of Fano resonance and bound states in continuum in a correlated double-quantum-dot system

Rajput¹,

Ahluwalia²,

Sharma³

2011

EPL

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We study the partial swapping of the Fano resonance in a correlated double-quantumdot (DQD) system connected to normal leads by employing the Keldysh non-equilibrium Green function technique in a Coulomb blockade regime. Two types of asymmetries have been considered which occurs when the DQD system undergoes transition from symmetric parallel to i) series and ii) T-shape geometries. It is found that both types of asymmetries exhibit swapping on varying the interdot Coulomb interaction (U12), however, mostly in the first one or first two pairs (out of four pairs) of Fano and Breit-Wigner peaks. Further, for particular values of U12 and dot-lead couplings, one, two or three Fano peaks collapse forming bound states in the continuum (BIC). This partial (non-magnetic) swapping and the formation of BIC is found to result from an interplay of correlation effects and asymmetries in dot-lead couplings.

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“…The equations for them generate third order Green's functions and so on. To receive closed set of equations the decoupling scheme of You and Zheng [42,43,53] is used.…”

Section: The Retarded Green's Function Of the Qqd Structure With The mentioning

confidence: 99%

“…Solving the system (25) and using the notations of [53] we get in non-magnetic case, n iσ = n iσ , a + iσ a jσ = a + iσ a jσ , the following expressions for the matrix elements of Ĝr ,…”

Section: Nonequilibrium Green's Functions In the Tight Binding Approachmentioning

confidence: 99%

Effects of anisotropy and Coulomb interactions on quantum transport in a quadruple quantum-dot structure

2017

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We present analytical and numerical investigation of spectral and transport properties of a quadruple quantum-dot (QQD) structure which is one of the popular low-dimensional systems in the context of fundamental quantum physics study, future electronic applications and quantum calculations. The density of states, occupation numbers and conductance of the structure were analyzed using the nonequilibrium Green's functions in the tight binding approach and the equation-of-motion method. In particular the anisotropy of hopping integrals and on-site electron energies as well as the effects of the finite intraand interdot Coulomb interactions were investigated. It was found out that the anisotropy of the kinetic processes in the system leads to the Fano-Feshbach asymmetrical peak. We demonstrated that the conductance of QQD device has a wide insulating band with steep edges separating triple-peak structures if the intradot Coulomb interactions are taken into account. The interdot Coulomb correlations between the central QDs result in the broadening of this band and the occurrence of an additional band with low conductance due to the Fano antiresonances. It was shown that in this case the conductance of the anisotropic QQD device can be dramatically changed by tuning the anisotropy of on-site electron energies.

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Zero bias maximum of differential conductance in coupled quantum dots: The effect of interdot Coulomb interaction

Cited by 11 publications

References 28 publications

Fano effect dominance over Coulomb blockade in transport properties of parallel coupled quantum dot system

Fano effect dominance over Coulomb blockade in transport properties of parallel coupled quantum dot system

Partial swapping of Fano resonance and bound states in continuum in a correlated double-quantum-dot system

Effects of anisotropy and Coulomb interactions on quantum transport in a quadruple quantum-dot structure

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