A phenomenological model for charge transport in extrinsic semiconductors is presented. For shallow impurities, large saturated impact-ionization coefficient and sufficiently low lattice temper­ ature, the current-field characteristic is S-shaped (SNDC) due to the interplay between impact ionization and scattering of carriers from acoustic phonons, ionized and neutral impurities. The present mo...

A system of two exchange-coupled Kondo impurities in a magnetic field gives rise to a rich phase space hosting a multitude of correlated phenomena. Magnetic atoms on surfaces probed through scanning tunnelling microscopy provide an excellent platform to investigate coupled impurities, but typical high Kondo temperatures prevent field-dependent studies from being performed, rendering large parts...

We present first-principles calculations of quantum transport which show that the resistance of metallic carbon nanotubes can be changed dramatically with homogeneous transverse electric fields if the nanotubes have impurities or defects. The change of the resistance is predicted to range over more than 2 orders of magnitude with experimentally attainable electric fields. This novel property ha...

Zn and Ni impurities in the hole-doped high-temperature superconductors are known to have strong effects on thermodynamic and transport properties. A recent scanning tunneling microscope study of Zn-doped Bi2212 (Pan et al., Nature 403, 746 (2000)) has provided high-resolution images of the local density of states around non-magnetic impurities in dx2−y2-wave superconductors. These pictures con...

For a system of noninteracting electrons scattered by neutral impurities, we derive a modified Boltzmann equation that includes quasiparticle and virial corrections. We start from a quasiclassical transport equation for nonequilibrium Green’s functions and apply a limit of small scattering rates. The resulting transport equation for quasiparticles has gradient corrections to scattering integral...