Related papers: Kondo Screening Cloud and Charge Quantization in M…
Magnetic impurities embedded in a metal are screened by the Kondo effect, signaled by the formation of an extended correlation cloud, the so-called Kondo or screening cloud. In a superconductor, the Kondo state turns into sub-gap…
We study the interplay between Coulomb blockade and the Kondo effect in quantum dots. We use a self-consistent scheme which describes mesoscopic devices in terms of a collective phase variable (slave rotor) and quasiparticle degrees of…
A magnetic moment in a metal or in a quantum dot is, at low temperatures, screened by the conduction electrons through the mechanism of the Kondo effect. This gives rise to spin-spin correlations between the magnetic moment and the…
We present a simple classification of the different liquid and solid phases of quantum Hall systems in the limit where the Coulomb interaction between the electrons is significant, i.e. away from integral filling factors. This…
We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect and the conductance reaches the unitary-limit…
We investigate a minimal system consisting of a quantum dot coupled to a Majorana zero mode and a normal lead. We identify the underlying screening process as a novel spin-charge Kondo effect, where the low-energy spin and charge degrees of…
We analyse the role which the distance scale $\xi_K = v_F/T_K$ plays in the single-impurity Kondo problem using renormalization group improved perturbation theory. We derive the scaling functions for the local spin susceptibility in various…
We analyze the screening of a magnetic quantum dot with spin 1/2 coupled to two helical liquids. Interestingly, we find two qualitatively different sets of Toulouse points, i.e., nontrivial parameters for which we can solve the two channel…
We analyze the equilibrium transport properties of underscreened Kondo effect in the case of a two-level quantum dot coupled to ferromagnetic leads. Using the numerical renormalization group (NRG) method, we have determined the gate voltage…
We demonstrate a tunable Kondo effect realized in small quantum dots. We can switch our dot from a Kondo impurity to a non-Kondo system as the number of electrons on the dot is changed from odd to even. We show that the Kondo temperature…
Orbital Kondo effect in a system of two single-level quantum dots attached to external electron reservoirs is considered theoretically. The dots are coupled via direct hoping term and Coulomb interaction. The Kondo temperature is evaluated…
We analyze the Kondo effect of a magnetic impurity attached to an ultrasmall metallic wire using the density matrix renormalization group. The spatial spin correlation function and the impurity spectral density are computed for system sizes…
Transport measurements at cryogenic temperatures through a few electron top gated quantum dot fabricated in a silicon/silicon-germanium heterostructure are reported. Variations in gate voltage induce a transition from an isolated dot toward…
We theoretically study enhancement mechanisms of the Kondo effect in multilevel quantum dots. In quantum dots fabricated on semiconductors, the energy difference between discrete levels \Delta is tunable by applying a magnetic field. With…
The charging of a quantum box connected to a lead by a single-mode point contact is solved for arbitrary temperatures, tunneling amplitudes, and gate voltages, using a variant of Wilson's numerical renormalization group. The charge inside…
We consider the thermodynamics of a uniformly charged polyelectrolyte with harmonic bonds. For such a system there is at high temperatures an approximate scaling of global properties like the end-to-end distance and the interaction energy…
Probing the universal low temperature magnetic field scaling of Kondo-correlated quantum dots via electrical conductance has proved to be experimentally challenging. Here, we show how to probe this in nonlinear thermocurrent spectroscopy…
Driving a quantum system at finite frequency allows one to explore its dynamics. This has become a well mastered resource for controlling the quantum state of two level systems in the context of quantum information processing. However, this…
We develop a general method to evaluate the Kondo temperature in a multilevel quantum dot that is weakly coupled to conducting leads. Our theory reveals that the Kondo temperature is strongly enhanced when the intradot energy-level spacing…
We study the spatial distribution of the Kondo screening cloud. We find that in 3 D the spatial range of the cloud is limited to distances of the order of the Fermi wavelength due to angular dispersion effects. In lower dimensions this…