Avalanches and the renormalization group for pinned charge-density waves.

Critical behavior of charge-density waves below threshold: Numerical and scaling analysis.

The critical behavior of pinned charge density waves (CDW’s) is studied as the threshold for sliding is approached. Using the Fukuyama-Lee-Rice Hamiltonian with relaxational dynamics, the polarization and linear response are calculated numerically. Analytic bounds on the subthreshold motion are used to develop fast numerical algorithms for evolving the CDW configuration. Two approaches to thres...

Time-Dependent Real-Space Renormalization Group Method

In this paper, using the tight-binding model, we extend the real-space renormalization group method to time-dependent Hamiltonians. We drive the time-dependent recursion relations for the renormalized tight-binding Hamiltonian by decimating selective sites of lattice iteratively. The formalism is then used for the calculation of the local density of electronic states for a one dimensional quant...

Collective Transport in Random Media: From Superconductors to Earthquakes

In these lectures, a variety of non-equilibrium transport phenomena are introduced that all involve, in some way, elastic manifolds being driven through random media. A simple class of models is studied focussing on the behavior near to the critical “depinning” force above which persistent motion occurs in these systems. A simple mean field theory and a “toy” model of “avalanche” processes are ...

X - Ray Diffraction from Pinned Charge Density Waves

We present an x-ray study of doped charge density waves systems. When a 2k f-charge density wave is strongly pinned to impurities, an interference effect gives rise to an asymmetry between the intensities of the +2k f and −2k f satellite reflections. Moreover, profile asymmetry of the satellite reflections indicates the existence of Friedel oscillations (FOs) around the defects. We have studied...

Scanning tunneling microscopy at the NbSe3 surface: Evidence for interaction between q(1) and q(2) charge density waves in the pinned regime