Related papers: Local moment formation in quantum point contacts
We study the formation of local magnetic moments in quantum point contacts. Using a Hubbard-like model to describe point contacts formed in a two dimensional system, we calculate the magnetic moment using the unrestricted Hartree…
We present results for a model that describes a quantum point contact. We show how electron-electron correlations, within the unrestricted Hartree-Fock approximation, generate a magnetic moment in the point contact. Having characterized the…
This is a three step work: i) we explain why quantum point contacts are similar to ballistic quantum dots; ii) we introduce the virtual Kondo state in both systems; iii-1st) this state explains 0.7 structure in point contacts; iii-2nd)…
We apply the non-equilibrium functional renormalization group approach treating flow of the electronic self-energies, to describe local magnetic moments formation and electronic transport in a quadruple quantum dot (QQD) ring, coupled to…
We develop a theoretical model for the description of electron dynamics in coupled quantum wires when the local magnetic moment is formed in one of the wires. We employ a single-particle Hamiltonian that takes account of the specific…
We study local moment formation in the presence of superconducting correlations among the f-electrons in the periodic Anderson model. Local moments form if the Coulomb interaction U>U_cr. We find that U_cr is considerably stronger in the…
We study the influence of many-body interactions on the transport characteristics of a novel device structure, consisting of a pair of quantum wires that are coupled to each other by means of a quantum dot. Under conditions where a local…
Quantum phase transitions (QPTs) arise as a result of competing interactions in a quantum many-body system. Kondo lattice models, containing a lattice of localized magnetic moments and a band of conduction electrons, naturally feature such…
Linear conductance below $2e^2/h$ shows resonance peaks in highly asymmetric quantum point contacts (QPCs). As the channel length increases, the number of peaks also increases. At the same time, differential conductance exhibits zero bias…
This set of four lectures was originally given at the VI Training Course in the Physics of Correlated Electron systems and High-Tc Superconductors, at Vietri Sur Mare, Italy (Oct 2001). The lectures are at an introductory level with…
The impact of Coulomb interaction on the electronic properties of a quantum spin-Hall insulator is studied using quantum cluster methods, disentangling local from non-local effects. We identify different regimes, according to the value of…
We derive expressions for the expectation values of the local energy and the local power transferred by an external electrical field to a many-particle system of interacting spinless electrons. In analogy with the definition of the (local)…
The Kondo effect is a key many-body phenomenon in condensed matter physics. It concerns the interaction between a localised spin and free electrons. Discovered in metals containing small amounts of magnetic impurities, it is now a…
We study the time evolution of two electron spin states in a double quantum-dot system, which includes a nearby quantum point contact (QPC) as a measurement device. We obtain that the QPC measurement induced decoherence is in time scales of…
We study the local moment formation and the Kondo effect at single-atom vacancies in Graphene. We develop a model accounting for the vacancy reconstruction as well as non-planarity effects induced by strain and/or temperature. Thus, we find…
We consider the Kondo effect in quantum dots coupled to Luttinger liquid leads, focussing on the case of repulsive interactions and spin SU(2) symmetry in the leads. We find that the system can flow to the 1-channel or 2-channel Kondo fixed…
The effective interaction between magnetic impurities in metals that can lead to various magnetic ground states often competes with a tendency for electrons near impurities to screen the local moment (Kondo effect). The simplest system…
Non-equilibrium spin transport through an interacting quantum dot is analyzed. The coherent spin oscillations in the dot provide a generating source for spin current. In the interacting regime, the Kondo effect is influenced in a…
We found analytical solution for the time evolution of localized electron density in a system of two coupled single-level quantum dots (QDs) connected with continuous spectrum states in the presence of Coulomb interaction. This solution…
We consider a mechanism of spin decay for an electron spin in a quantum dot due to coupling to a nearby quantum point contact (QPC) with and without an applied bias voltage. The coupling of spin to charge is induced by the spin-orbit…