Fano stability diagram of a symmetric triple quantum dot

Niklas, Michael; Trottmann, Andreas; Donarini, Andrea; Grifoni, Milena

doi:10.1103/physrevb.95.115133

Cited by 30 publications

(34 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since in such a ring, the electrons may be transported by direct tunneling from the first to the last dot or via dot 2, the conductance is governed by interference [32,33] and may suffer from decoherence [34]. Here we consider a gate voltage that shifts the on-site energy of dot 2 by such that the corresponding single-particle Hamiltonian reads…”

Section: Triple Quantum Dot In a Ring Configurationmentioning

confidence: 99%

Full-counting statistics of time-dependent conductors

2016

Self Cite

View full text Add to dashboard Cite

We develop a scheme for the computation of the full-counting statistics of transport described by Markovian master equations with an arbitrary time dependence. It is based on a hierarchy of generalized density operators, where the trace of each operator yields one cumulant. This direct relation offers a better numerical efficiency than the equivalent number-resolved master equation. The proposed method is particularly useful for conductors with an elaborate time dependence stemming, e.g., from pulses or combinations of slow and fast parameter switching. As a test bench for the evaluation of the numerical stability, we consider time-independent problems for which the full-counting statistics can be computed by other means. As applications, we study cumulants of higher order for two time-dependent transport problems of recent interest, namely steady-state coherent transfer by adiabatic passage (CTAP) and Landau-Zener-Stückelberg-Majorana (LZSM) interference in an open double quantum dot.

show abstract

Section: Triple Quantum Dot In a Ring Configurationmentioning

confidence: 99%

Full-counting statistics of time-dependent conductors

2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…20 and 21 the energy splitting for triangle molecule in Table I is always positive for the dot confinement d < R 1 √ 2π ≃ 2.5R 1 which is true in this case. We mention also that in [59] the exact results for a triangle are calculated and our results are recovered in the limit U H − V (R 1 ) ≪ |t|.…”

Section: Examplesmentioning

confidence: 57%

Hund and anti-Hund rules in circular molecules

et al. 2017

View full text Add to dashboard Cite

We study the validity of Hund's first rule for the spin multiplicity in circular molecules -made of real or artificial atoms such as quantum dots -by considering a perturbative approach in the Coulomb interaction in the extended Hubbard model with both on-site and long-range interactions. In this approximation, we show that an anti-Hund rule always defines the ground state in a molecule with 4N atoms at half-filling. In all other cases (i.e. number of atoms not multiple of four, or a 4N molecule away from half-filling) both the singlet and the triplet outcomes are possible, as determined primarily by the total number of electrons in the system. In some instances, the Hund rule is always obeyed and the triplet ground state is realized mathematically for any values of the on-site and long range interactions, while for other filling situations the singlet is also possible but only if the long-range interactions exceed a certain threshold, relatively to the on-site interaction.

show abstract

“…The properties of triple quantum dot systems have been extensively studied in various regimes and configurations, exposing rich Kondo physics [8][9][10][11], various transport effects and complex electron structure [12][13][14][15][16][17], as well as revealing potential for applications in quantum computing [18][19][20][21][22] and for generation of non-local, entangled electron pairs [23,24]. When the three quantum dots form a triangular geometry [25][26][27][28][29][30][31], the system resembles a simple planar molecule and, due to the interference effects, the formation of dark states is possible [32][33][34][35][36][37]. This quantum-mechanical phenomenon was first observed in atomic physics [38][39][40][41], and then found also in mesoscopic systems, such as, in particular, coupled quantum dots [42,43].…”

Section: Introductionmentioning

confidence: 99%

Dark states in spin-polarized transport through triple quantum dot molecules

Wrześniewski

Weymann

2018

Phys. Rev. B

View full text Add to dashboard Cite

We study the spin-polarized transport through a triple quantum dot molecule weakly coupled to ferromagnetic leads. The analysis is performed by means of the real-time diagrammatic technique including up to the second order of perturbation expansion with respect to the tunnel coupling. The emphasis is put on the impact of dark states on spin-resolved transport characteristics. It is shown that the interplay of coherent population trapping and cotunneling processes results in a highly nontrivial behavior of the tunnel magnetoresistance, which can take negative values. Moreover, a super-Poissonian shot noise is found in transport regimes where the current is blocked by the formation of dark states, which can be additionally enhanced by spin-dependence of tunneling processes, depending on magnetic configuration of the device. The mechanisms leading to those effects are thoroughly discussed. arXiv:1802.02484v1 [cond-mat.mes-hall]

show abstract

Fano stability diagram of a symmetric triple quantum dot

Cited by 30 publications

References 37 publications

Full-counting statistics of time-dependent conductors

Full-counting statistics of time-dependent conductors

Hund and anti-Hund rules in circular molecules

Dark states in spin-polarized transport through triple quantum dot molecules

Contact Info

Product

Resources

About