Related papers: Kondo Screening Cloud and Charge Quantization in M…
We study finite-temperature properties of the Kondo effect in a carbon nanotube (CNT) quantum dot using the Wilson numerical renormalization group (NRG). In the absence of magnetic fields, four degenerate energy levels of the CNT consisting…
Continuously monitoring a quantum system can strongly affect its properties and even suppress its coherent evolution via the Quantum Zeno effect. Well understood for few body quantum systems, the role of quantum measurements on entangled…
We derive the topological Kondo Hamiltonian describing a Y junction of three XX-spin chains connected to outer quantum Ising chains with different tilting angles for the Ising axis. We show that the tilting angles in the spin models play…
We investigate the boundary phenomena that arise in a finite-size $XX$ spin chain interacting through an $XX$ interaction with a spin$-\frac{1}{2}$ impurity located at its edge. Upon Jordan-Wigner transformation, the model is described by a…
We analyze the transport properties of a double quantum dot device in the side-coupled configuration. A small quantum dot (QD), having a single relevant electronic level, is coupled to source and drain electrodes. A larger QD, whose…
We investigate the charge fluctuations of a grain (large dot) coupled to a lead via a small quantum dot in the Kondo regime. We show that the strong entanglement of charge and spin flips in this setup can result in a stable SU(4) Kondo…
We have measured the temperature dependence of the conductivity $\sigma_{xx}$ of a two-dimensional electron system deep into the localized regime of the quantum Hall plateau transition. Using variable-range hopping theory we are able to…
By coupling on chip a carbon nanotube to a quantum noise detector, a superconductor-insulator-superconductor junction, via a resonant circuit, we measure the emission noise of a carbon nanotube quantum dot in the Kondo regime. The signature…
We study a generalized Kondo model in which a spin-1/2 impurity is coupled to a conduction band by both s-d exchange and potential interactions. A strong potential scattering is shown to screen an exchange scattering, and the Kondo…
The system described in this work consists of a quantum dot inserted in a mesoscopic ring threaded by a magnetic flux. Our aim is to present a complete description for this device and to predict the physics of a experiment with these…
We use an efficient projection scheme for the Fock operator to analyze the size dependence of silicon quantum dots (QDs) electronic properties. We compare the behavior of hybrid, screened hybrid and local density functionals as a function…
We investigate a mesoscopic setup composed of a small electron droplet (dot) coupled to a larger quantum dot (grain) also subject to Coulomb blockade as well as two macroscopic leads used as source and drain. An exotic Kondo ground state…
In this work,we study the Kondo effect of a quantum dot (QD) connected to leads and to a discrete set of one particle states provided by a quantum box represented by a quantum ring (QR) pierced by a magnetic flux side attached to the QD.…
When described in a grand canonical ensemble, a finite Coulomb system exhibits charge fluctuations. These fluctuations are studied in the case of a classical (i.e. non-quantum) system with no macroscopic average charge. Assuming the…
We investigate the influence of an electromagnetic environment, characterized by a finite impedance $Z(\omega)$, on the Kondo effect in quantum dots. The circuit voltage fluctuations couple to charge fluctuations in the dot and influence…
The Kondo effect, an eminent manifestation of many-body physics in condensed matter, is traditionally explained as exchange scattering of conduction electrons on a spinful impurity in a metal. The resulting screening of the impurity's local…
We investigate the properties of the molecular quantum dot (Holstein-Anderson) model using numerical and analytical techniques. Path integral Monte Carlo simulations for the cumulants of the distribution function of the phonon coordinate…
A quantum dot coupled to ferromagnetically polarized one-dimensional leads is studied numerically using the density matrix renormalization group method. Several real space properties and the local density of states at the dot are computed.…
Using the perturbative scaling and the NRG, we study the characteristic energy scales in the Kondo impurity problem as a function of the exchange coupling constant $J$ and the conduction electron density. We discuss the relation between the…
We investigate theoretically the linear conductance of a two-level quantum dot as a function of the gate voltage and different strength of coupling to the external electronic system (the reservoir). Apart from the weak coupling regime,…