Dynamic structure factor in impurity-doped spin chains

Effects of different impurity types in spin-chains

Abstract. Using the density matrix renormalization group (DMRG) method, we study the quantum coherence in one-dimensional disordered Fermi systems. We consider in detail spinless fermions on a ring, and compare the influence of several kinds of impurities in a gapless and a dimerized, gapped system. In the translation-invariant system a so-called site-impurity, which can be realized by a local ...

Spin relaxation in n-doped gallium arsenide due to impurity and electron-electron Elliot-Yafet scattering

We calculate the spin relaxation time of conduction electrons in n-doped bulk gallium arsenide. We consider the Elliot-Yafet spin-relaxation mechanism, driven by Coulombic-impurity and electron-electron scattering. We find that these two scattering mechanisms result in relaxation times of equal order of magnitude, but with disimilar dependences on doping density and temperature. Our theoretical...

Impurity-free disordering mechanisms in GaAs-based structures using doped spin-on silica layers

The structure of conserved charges in open spin chains

We study the local conserved charges in integrable spin chains of the XYZ type with nontrivial boundary conditions. The general structure of these charges consists of a bulk part, whose density is identical to that of a periodic chain, and a boundary part. In contrast with the periodic case, only the charges corresponding to the interactions of even number of spins exist for the open chain. Hen...

Crossed spin-1/2 heisenberg chains as a quantum impurity problem.

Using equivalencies between different models we reduce the model of two spin-1/2 Heisenberg chains crossed at one point to the model of free fermions. The spin-spin correlation function is calculated by summing the perturbation series in the interchain interaction. The result reveals a power law decay with a nonuniversal exponent.