Dias da Silva<i>et al.</i>Reply:

Silva, Luis G. G. V. Dias da; Sandler, Nancy; Ingersent, Kevin; Ulloa, Sergio E.

doi:10.1103/physrevlett.99.209702

Cited by 56 publications

(133 citation statements)

References 2 publications

Supporting

Mentioning

124

Contrasting

Order By: Relevance

“…Pseudogap Kondo physics has previously been predicted to occur in doublequantum-dot devices [12,13], but the ring geometry of the present setup allows a deeper exploration of the interplay between coherent quantum interference and the Kondo effect. The conductance and transmission phase shift through the system exhibit clear signatures of each zero-temperature transition within a quantum-critical region that extends up to temperatures of order the maximum Kondo scale of the interacting dot.…”

mentioning

confidence: 99%

“…For a general flux, A 11 (ω) features a Kondo resonance centered on ω = 0. For Φ = nΦ 0 , however, A 11 (ω) vanishes at ω = 0, signaling suppression of the Kondo effect by the pseudogap in ρ eff (ω) [12].…”

mentioning

confidence: 99%

“…Quantum phase transitions.-As noted in the introduction, the presence of a pseudogap in ρ eff (ω) gives rise to a pair of QPTs separating Kondo and local-moment phases [12,13]. These QPTs occur in the double-dot AB setup for Φ = nΦ 0 and ε 2 = 0 when ε 1 is tuned to one of two critical values ε ± 1c .…”

mentioning

confidence: 99%

See 2 more Smart Citations

Tunable Pseudogap Kondo Effect and Quantum Phase Transitions in Aharonov-Bohm Interferometers

et al. 2009

Self Cite

View full text Add to dashboard Cite

We study two quantum dots embedded in the arms of an Aharonov-Bohm ring threaded by a magnetic flux. The system can be described by an effective one-impurity Anderson model with an energy-and flux-dependent density of states. For specific values of the flux, this density of states vanishes at the Fermi energy, yielding a controlled realization of the pseudogap Kondo effect. The conductance and transmission phase shifts reflect a nontrivial interplay between wave interference and interactions, providing clear signatures of quantum phase transitions between Kondo and nonKondo ground states. Nanoscale quantum-dot devices are a formidable tool for probing the inherent quantum-mechanical nature of electrons. Manifestations of quantum electronic properties in these devices include wave interference in Aharonov-Bohm (AB) rings [1, 2, 3] and many-body phenomena such as the Kondo effect (the screening of a localized magnetic moment by conduction electrons) [3,4,5,6] and quantum phase transitions (QPTs) [6]. The interplay between quantum interference and the Kondo effect can be studied by inserting a quantum dot in an AB ring, as shown both experimentally [5] and theoretically [7,8,9].This Letter focuses on a system in which two quantum dots are embedded in the same AB ring. Interesting effects have been proposed [8] in cases where both dots are in the Kondo regime. Here, we consider instead a device in which the presence of one, effectively noninteracting dot creates for a second, Kondo-regime dot, an energy-dependent effective density of states that depends on the magnetic flux applied through the ring. Varying this flux can dramatically affect the Kondo state in the interacting dot, causing the Kondo temperature T K -the characteristic energy scale of the Kondo state-to range over many orders of magnitude.This two-dot AB device can also realize the conditions necessary for observation of the pseudogap Kondo effect [10,11], in which coupling of a magnetic impurity to a power-law-vanishing density of conduction states gives rise to a pair of QPTs between Kondo (T K > 0) and non-Kondo (T K = 0) phases. Pseudogap Kondo physics has previously been predicted to occur in doublequantum-dot devices [12,13], but the ring geometry of the present setup allows a deeper exploration of the interplay between coherent quantum interference and the Kondo effect. The conductance and transmission phase shift through the system exhibit clear signatures of each zero-temperature transition within a quantum-critical region that extends up to temperatures of order the maximum Kondo scale of the interacting dot. This robustness plus the relative ease of experimental control make the proposed device very promising for experimental investigation of pseudogap Kondo physics.Model.-Quantum dots ("1" and "2") are embedded in opposite arms of an AB interferometer that is connected to left ("L") and right ("R") metallic leads, as shown in Fig. 1(a). Dot 1 is in a Coulomb blockade valley and is occupied by an odd number of electrons, while dot 2 has a si...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Tunable Pseudogap Kondo Effect and Quantum Phase Transitions in Aharonov-Bohm Interferometers

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…[9][10][11] This interaction is responsible for several fascinating phenomena, e.g., Coulomb blockade, 11,12 and Kondo effect, 7,13,14 leading to characteristic behavior of the thermodynamical and transport properties, which depend drastically on the number of QDs, as well as on their topological configuration in the structure. In recent years, strong on-site interaction in double 13,[15][16][17][18][19][20][21][22][23][24] and triple [25][26][27][28][29][30][31][32] QD (DQD and TQD) structures have received a great deal of attention when in the Kondo regime. However, on-site electron-electron interaction does not exhaust all the possibilities in multiple QD structures, as electrons can, due to their proximity, interact with each other, even when located in different QDs.…”

Section: Introductionmentioning

confidence: 99%

Capacitively coupled double quantum dot system in the Kondo regime

et al. 2011

View full text Add to dashboard Cite

A detailed study of the low-temperature physics of an interacting double quantum dot system in a T-shape configuration is presented. Each quantum dot is modeled by a single Anderson impurity and we include an inter-dot electron-electron interaction to account for capacitive coupling that may arise due to the proximity of the quantum dots. By employing a numerical renormalization group approach to a multi-impurity Anderson model, we study the thermodynamical and transport properties of the system in and out of the Kondo regime. We find that the two-stage-Kondo effect reported in previous works is drastically affected by the inter-dot Coulomb repulsion. In particular, we find that the Kondo temperature for the second stage of the two-stage-Kondo effect increases exponentially with the inter-dot Coulomb repulsion, providing a possible path for its experimental observation.

show abstract

“…In papers [4,5] the single impurity and double impurity Anderson models have been used to study the electric conductance of the systems with quantum dots and the magnetic ordering in a band electron subsystem was found crucially important for the spin-dependent transport through a quantum dot. In this paper, an eective Hamiltonian taking into account basic interactions in the localized electron subsystem as well as hybridization between the localized and band electrons is used to study the electrical properties of the AndersonHubbard material.…”

Section: Introductionmentioning

confidence: 99%

Phase Diagram of Metal-Insulator Transition in System with Anderson-Hubbard Centers

et al. 2012

View full text Add to dashboard Cite

The model of a strongly correlated system in which periodically spaced AndersonHubbard centers are introduced into narrow-band metal is considered. Besides the interactions between localized magnetic moments and strong on-site Coulomb interaction, the model takes into account the hybridization of localized and band states. To study the eect of the lattice deformation on the electrical properties of the system, the phonon term and elastic energy have been taken into account. Green functions for band and localized electrons have been found. On this base, the energy spectrum has been investigated as a function of model parameters, temperature and external pressure. The criterion of the metalinsulator transition for an integer value of electron concentration has been derived and the phase diagram of the metalinsulator transition has been built.

show abstract

Dias da Silvaet al.Reply:

Cited by 56 publications

References 2 publications

Tunable Pseudogap Kondo Effect and Quantum Phase Transitions in Aharonov-Bohm Interferometers

Tunable Pseudogap Kondo Effect and Quantum Phase Transitions in Aharonov-Bohm Interferometers

Capacitively coupled double quantum dot system in the Kondo regime

Phase Diagram of Metal-Insulator Transition in System with Anderson-Hubbard Centers

Contact Info

Product

Resources

About