Charge transport through single molecules, quantum dots and quantum wires

Andergassen, Sabine; Meden, V.; Schoeller, Herbert; Splettstoesser, Janine; Wegewijs, M. R.

doi:10.1088/0957-4484/21/27/272001

Cited by 109 publications

(105 citation statements)

References 238 publications

(440 reference statements)

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“…At appropriate conditions, these systems consist of discrete energy levels of quantum dots, which are hybridized with the leads, having continuous energy bands. It is well known that physical properties of such zero-dimensional structures are strongly influenced by Coulomb electron interaction effects, leading to non-trivial interactioninduced effects [16][17][18] (e.g., the Kondo effect [19]). …”

Section: Introductionmentioning

confidence: 99%

Functional renormalization group study of parallel double quantum dots: Effects of asymmetric dot-lead couplings

Проценко

Катанин

2017

Phys. Rev. B

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We explore the effects of asymmetry of hopping parameters between double parallel quantum dots and the leads on the conductance and a possibility of local magnetic moment formation in this system using functional renormalization group approach with the counterterm. We demonstrate a possibility of a quantum phase transition to a local moment regime (so called singular Fermi liquid (SFL) state) for various types of hopping asymmetries and discuss respective gate voltage dependences of the conductance. It is shown, that depending on the type of the asymmetry, the system can demonstrate either a first order quantum phase transition to SFL state, accompanied by a discontinuous change of the conductance, similarly to the symmetric case, or the second order quantum phase transition, in which the conductance is continuous and exhibits Fano-type asymmetric resonance near the transition point. A semi-analytical explanation of these different types of conductance behavior is presented.

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Section: Introductionmentioning

confidence: 99%

Functional renormalization group study of parallel double quantum dots: Effects of asymmetric dot-lead couplings

Проценко

Катанин

2017

Phys. Rev. B

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“…The search for new paradigms in electronics has spurred interest in other quantum phenomena at the nanoscale: electron correlations offer the promise of new functionality in nanoelectronics related to the possible manipulation of manybody ground states in suitably produced nanostructures such as quantum dots and nanoribbons [12][13][14] . An important example that has attracted a great deal of attention is the Kondo state, realized by coupling a magnetic impurity to conduction electrons [see, for example, section VII of Ref.…”

Section: Introductionmentioning

confidence: 99%

Spatial structure of correlations around a quantum impurity at the edge of a two-dimensional topological insulator

2017

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We calculate exact zero-temperature real space properties of a substitutional magnetic impurity coupled to the edge of a zigzag silicene-like nanoribbon. Using a Lanczos transformation [Phys. Rev. B 91, 085101 (2015)] and the density matrix renormalization group method, we obtain a realistic description of stanene and germanene that includes the bulk and the edges as boundary one-dimensional helical metallic states. Our results for substitutional impurities indicate that the development of a Kondo state and the structure of the spin correlations between the impurity and the electron spins in the metallic edge state depend considerably on the location of the impurity. More specifically, our real space resolution allows us to conclude that there is a sharp distinction between the impurity being located at a crest or a trough site at the zigzag edge. We also observe, as expected, that the spin correlations are anisotropic due to an emerging Dzyaloshinskii-Moriya interaction with the conduction electrons, and that the edges scatter from the impurity and "snake" or circle around it. Our estimates for the Kondo temperature indicate that there is a very weak enhancement due to the presence of spin-orbit coupling.

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“…Further, let us take c 1 (0) = c 10 and c 2 (0) = c 20 ; we will assume that the deviations of c 1 (t) and c 2 (t) from c 10 and c 20 respectively will be of order V at all values of t. At first order, we can replace c 1 (t) and c 2 (t) by c 10 and c 20 on the right hand sides in Eqs. (42). This gives …”

Section: Resonant Case With Ementioning

confidence: 90%

Nonadiabatic charge pumping by oscillating potentials in one dimension: Results for infinite system and finite ring

Soori

Sen

2010

Phys. Rev. B

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We study charge pumping when a combination of static potentials and potentials oscillating with a time period T is applied in a one-dimensional system of non-interacting electrons. We consider both an infinite system using the Dirac equation in the continuum approximation, and a periodic ring with a finite number of sites using the tight-binding model. The infinite system is taken to be coupled to reservoirs on the two sides which are at the same chemical potential and temperature. We consider a model in which oscillating potentials help the electrons to access a transmission resonance produced by the static potentials, and show that non-adiabatic pumping violates the simple sin φ rule which is obeyed by adiabatic two-site pumping. For the ring, we do not introduce any reservoirs, and we present a method for calculating the current averaged over an infinite time using the time evolution operator U (T ) assuming a purely Hamiltonian evolution. We analytically show that the averaged current is zero if the Hamiltonian is real and time reversal invariant. Numerical studies indicate another interesting result, namely, that the integrated current is zero for any time-dependence of the potential if it is applied to only one site. Finally we study the effects of pumping at two sites on a ring at resonant and non-resonant frequencies, and show that the pumped current has different dependences on the pumping amplitude in the two cases.

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Charge transport through single molecules, quantum dots and quantum wires

Cited by 109 publications

References 238 publications

Functional renormalization group study of parallel double quantum dots: Effects of asymmetric dot-lead couplings

Functional renormalization group study of parallel double quantum dots: Effects of asymmetric dot-lead couplings

Spatial structure of correlations around a quantum impurity at the edge of a two-dimensional topological insulator

Nonadiabatic charge pumping by oscillating potentials in one dimension: Results for infinite system and finite ring

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