Electron transport through Aharonov-Bohm interferometer with laterally coupled double quantum dots

Abstract

We theoretically investigate electron transport through an Aharonov-Bohm interferometer containing laterally coupled double quantum dots. We introduce the indirect coupling parameter α, which characterizes the strength of the coupling via the reservoirs between two quantum dots. |α| = 1 indicates the strongest coupling, where only a single mode contributes to the transport in the system. Two conduction modes exist in a system where |α| = 1. The interference effects such as the Fano resonance and the Aharonov-Bohm oscillation are suppressed as the absolute value of the parameter α decreases from 1. The linear conductance does not depend on the flux when α = 0 since it corresponds to independent coupling of the dots to the reservoir modes.

Kondo effects and shot noise enhancement in a laterally coupled double quantum dot

“…α is a function of the propagation length s 12 of the electrons in the reservoir 43 , and in general, |α| ≤ 1. The condition s 12 = 0 is equivalent to α = 1 46 .…”

“…In contrast we concentrate on the competition between the Kondo exchnage and J α when ∆ǫ = 0 and α = 0 for the drain reservoir. If we investigate this competition when ∆ǫ = 0 and α = 1 for both the source and drain reservoirs, we expect the single channel Kondo effect (the exchange coupling caused by the coherent indirect coupling vanishes as shown in Appendix B) since there is only a single conduction mode in such a situation, namely one of the two orbital channels is in a dark state 43 . Here, although we considered the effect of the integrated reservoir only for the source, we can expect stronger suppression of the spin Kondo effect in the (1, 1) regime when both the source and drain reservoirs are integrated with 0 < |α| = 1.…”

“…43, the azimuthal integration gives rise to the oscillatory behavior of the coherent indirect coupling parameter with respect to the propagation length, and the radial integration is…”

Dephasing in an Aharonov–Bohm interferometer containing a lateral double quantum dot induced by coupling with a quantum dot charge sensor

“…2 we employ the standard tunneling Hamiltonian formalism to describe an AB interferometer containing a DQD that couples to a QD charge sensor, and provide the formulation needed to calculate the transport properties. In particular, we introduce the notion of coherent indirect coupling between two QDs via a reservoir [20,21]. In Sec.…”

Intra- and inter-shell Kondo effects in carbon nanotube quantum dots

“…The effect of contacts which may mix orbital numbers is thoroughly discussed in [41,43]. Indirect valley scattering via the electron states of electrodes can be represented by the off diagonal terms of electrode-dot coupling matrix Γ m,−m , and following [73,74] they can be approximated by Γ m,−m = iqΓ . The processes represented by off diagonal terms of Γ result from various interference effects and are the consequence of indirect transitions between dot orbitals by states in the electrodes.…”