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Electron cotunneling through doubly occupied quantum dots: effect of spin configuration.

Lan J, Sheng W - Nanoscale Res Lett (2011)

Bottom Line: A microscopic theory is presented for electron cotunneling through doubly occupied quantum dots in the Coulomb blockade regime.Beyond the semiclassic framework of phenomenological models, a fully quantum mechanical solution for cotunneling of electrons through a one-dimensional quantum dot is obtained using a quantum transmitting boundary method without any fitting parameters.Furthermore, it is found that the cotunneling conductance reveals more sensitive dependence on the barrier width than the height.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Furan University, Shanghai 200433, PR China. shengw@fudan.edu.cn.

ABSTRACT
A microscopic theory is presented for electron cotunneling through doubly occupied quantum dots in the Coulomb blockade regime. Beyond the semiclassic framework of phenomenological models, a fully quantum mechanical solution for cotunneling of electrons through a one-dimensional quantum dot is obtained using a quantum transmitting boundary method without any fitting parameters. It is revealed that the cotunneling conductance exhibits strong dependence on the spin configuration of the electrons confined inside the dot. Especially for the triplet configuration, the conductance shows an obvious deviation from the well-known quadratic dependence on the applied bias voltage. Furthermore, it is found that the cotunneling conductance reveals more sensitive dependence on the barrier width than the height.

No MeSH data available.


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Cotunneling conductance calculated as a function of the applied bias voltage for the dot occupied by a singlet (thin lines) and triplet (thick lines). The width of barriers is reduced to 2.5 from 5.0 nm.
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Figure 4: Cotunneling conductance calculated as a function of the applied bias voltage for the dot occupied by a singlet (thin lines) and triplet (thick lines). The width of barriers is reduced to 2.5 from 5.0 nm.

Mentions: Let us see next how the cotunneling conductance depends on the barrier width. Figure 4 plots the cotunneling conductance calculated as a function of the applied bias voltage for the dot of thinner barriers. With the width of barriers reduced by half, the cotunneling conductance is seen to be almost twice as larger as that with lower barriers. It can therefore be concluded that the dependence of the cotunneling conductance is more sensitive on the barrier width than the height.


Electron cotunneling through doubly occupied quantum dots: effect of spin configuration.

Lan J, Sheng W - Nanoscale Res Lett (2011)

Cotunneling conductance calculated as a function of the applied bias voltage for the dot occupied by a singlet (thin lines) and triplet (thick lines). The width of barriers is reduced to 2.5 from 5.0 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211313&req=5

Figure 4: Cotunneling conductance calculated as a function of the applied bias voltage for the dot occupied by a singlet (thin lines) and triplet (thick lines). The width of barriers is reduced to 2.5 from 5.0 nm.
Mentions: Let us see next how the cotunneling conductance depends on the barrier width. Figure 4 plots the cotunneling conductance calculated as a function of the applied bias voltage for the dot of thinner barriers. With the width of barriers reduced by half, the cotunneling conductance is seen to be almost twice as larger as that with lower barriers. It can therefore be concluded that the dependence of the cotunneling conductance is more sensitive on the barrier width than the height.

Bottom Line: A microscopic theory is presented for electron cotunneling through doubly occupied quantum dots in the Coulomb blockade regime.Beyond the semiclassic framework of phenomenological models, a fully quantum mechanical solution for cotunneling of electrons through a one-dimensional quantum dot is obtained using a quantum transmitting boundary method without any fitting parameters.Furthermore, it is found that the cotunneling conductance reveals more sensitive dependence on the barrier width than the height.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, Furan University, Shanghai 200433, PR China. shengw@fudan.edu.cn.

ABSTRACT
A microscopic theory is presented for electron cotunneling through doubly occupied quantum dots in the Coulomb blockade regime. Beyond the semiclassic framework of phenomenological models, a fully quantum mechanical solution for cotunneling of electrons through a one-dimensional quantum dot is obtained using a quantum transmitting boundary method without any fitting parameters. It is revealed that the cotunneling conductance exhibits strong dependence on the spin configuration of the electrons confined inside the dot. Especially for the triplet configuration, the conductance shows an obvious deviation from the well-known quadratic dependence on the applied bias voltage. Furthermore, it is found that the cotunneling conductance reveals more sensitive dependence on the barrier width than the height.

No MeSH data available.


Related in: MedlinePlus