Interference effects on Kondo-assisted transport through double quantum dots

Abstract

We systematically investigate electron transport through double quantum dots with particular emphasis on interference induced via multiple paths of electron propagation. By means of the slave-boson mean-field approximation, we calculate the conductance, the local density of states, the transmission probability in the Kondo regime at zero temperature. It is clarified how the Kondoassisted transport changes its properties when the system is continuously changed among the serial, parallel and T-shaped double dots. The obtained results for the conductance are explained in terms of the Kondo resonances influenced by interference effects. We also discuss the impacts due to the spin-polarization of ferromagnetic leads.

Interference effects in the counting statistics of electron transfers through a double quantum dot

“…Experimentally, it would correspond to spin polarized leads in an infinite magnetic field where only one spin state is accessible by electronic excitations. This spinless DQD model has been used to study the effect of interferences on average currents without [20][21][22] and with [25][26][27]30 an additional Aharonov-Bohm phase.…”

“…17,18 It has been shown that strong Coulomb interactions suppress large current fluctuations. 17 Double quantum dot ͑DQD͒ systems in parallel geometry [19][20][21][22] and single multilevel quantum dots 23,24 can display interference effects due to the multiple paths that electrons take to cross the junction when Coulomb interaction is present. These effects on the average electric current and level population [19][20][21][22][23][24] do not require a magnetic field as in double quantum dot Aharonov-Bohm interferometers.…”

“…17 Double quantum dot ͑DQD͒ systems in parallel geometry [19][20][21][22] and single multilevel quantum dots 23,24 can display interference effects due to the multiple paths that electrons take to cross the junction when Coulomb interaction is present. These effects on the average electric current and level population [19][20][21][22][23][24] do not require a magnetic field as in double quantum dot Aharonov-Bohm interferometers. [25][26][27][28][29][30] A recent study of interference effects on the electron transfer statistics showed that they can induce super-Poisson shot noise in the Coulomb blockade regime and the high bias limit.…”

Quantum phase transition and underscreened Kondo effect in electron transport through parallel double quantum dots

“…For the DQD system in parallel configuration, the physical properties can be quite different, since the interference effect will play an important role in its transport properties. The Fano effect for electron transport through bonding and antibonding channels in DQDs system has been studied [11,12,13].…”

Antisymmetric Spin–Orbit Coupling Effect on Kondo-Induced Electric Polarization in a Triangular Triple Quantum Dot

“…The Kondo physics has been extensively studied in a wide range of fields from d-or f -electron impurities embedded in bulk materials 2, 3) to artificial atomic systems with metallic lead contacts such as quantum dot (QD) or magnetic molecular devices. [4][5][6][7][8][9] In particular, much attention has been paid to rich Kondo phenomena associated with coupled spin clusters or fabricated quantum devices, for instance, the transport properties between leads through a double 4,6,[10][11][12][13][14][15] or triple QD. [16][17][18][19][20] As a different context, several theoretical studies have recently investigated the Kondo effect for a single impurity in two-dimensional electron gas with the Rashba spin-orbit (SO) coupling.…”