The appropriate generalization of the isotropic impurity Anderson model for va-lence fluctuations between two magnetic multiplets l n and l n+1 is solved in the strong-coupling limit of Wilson's renormalization group for l ≤ 3. Except in the extreme case of j − j coupling, the ground state is degenerate, the impurity magnetic moment is very small and is overscreened by the conduction electrons....

We report low-temperature measurements of electron decoherence time in a series of pure gold wires, 18 nm thick and 30 nm wide. At fields up to 15 T, large enough to polarize any concentration of magnetic impurity spins, conductance fluctuation measurements show almost no temperature dependence of the decoherence time below 300 mK, both in the correlation field for interference and the root-mea...

Systematic impurity doping in the Cu-O plane of the hole-doped cuprate superconductors may allow one to decide between unconventional (”d-wave”) and anisotropic conventional (”s-wave”) states as possible candidates for the order parameter in these materials. We show that potential scattering of any strength always increases the gap minima of such s-wave states, leading to activated behavior in ...

We study the impact of dynamical correlations on the electronic structure and coherent transport properties of Cu nanocontacts hosting a single magnetic impurity (Ni, Co, Fe) in the contact region. The strong dynamical correlations of the impurity 3d electrons are fully taken into account by combining density-functional calculations with a dynamical treatment of the impurity 3d shell in the one...

The magnetization and magnetoresistance of Si whiskers doped with to boron concentrations corresponding to the metal-insulator transition (2 × 1018 cm-3 ÷ 5 × 1018 cm-3) were measured at high magnetic fields up to 14 T in a wide temperature range 4.2-300 K. Hysteresis of the magnetic moment was observed for Si p-type whiskers with nickel impurity in a wide temperature range 4.2-300 K in...

We study the role of impurity scattering on the photoluminescence (PL) emission of polarized magnetoexcitons. We consider systems where both the electron and hole are confined on a ring structure (quantum rings) as well as on a type-II quantum dot. Despite their neutral character, excitons exhibit strong modulation of energy and oscillator strength in the presence of magnetic fields. Scattering...