arXiv subjects

Ludwig Schweitzer

Publications and source records attributed to Ludwig Schweitzer.

3 recordsLinked to original sources

arXiv2003

Frequency Dependent Electrical Transport in the Integer Quantum Hall Effect

The status of the ac quantum Hall effect is reviewed with emphasis on the theoretical development in recent years. In particular, the numerical approaches for the calculation of the frequency dependent Hall and longitudinal conductivities of non-interacting electrons are considered in detail. Results for the frequency scaling at the critical point and for the frequency dependent deviation of the Hall conductivity from the quantised plateau value are presented.

cond-mat.mes-hall↗

arXiv1996

Critical dynamics and multifractal exponents at the Anderson transition in 3d disordered systems

We investigate the dynamics of electrons in the vicinity of the Anderson transition in $d=3$ dimensions. Using the exact eigenstates from a numerical diagonalization, a number of quantities related to the critical behavior of the diffusion function are obtained. The relation $η= d-D_{2}$ between the correlation dimension $D_{2}$ of the multifractal eigenstates and the exponent $η$ which enters into correlation functions is verified. Numerically, we have $η\approx 1.3$. Implications of critical dynamics for experiments are predicted. We investigate the long-time behavior of the motion of a wave packet. Furthermore, electron-electron and electron-phonon scattering rates are calculated. For the latter, we predict a change of the temperature dependence for low $T$ due to $η$. The electron-electron scattering rate is found to be linear in $T$ and depends on the dimensionless conductance at the critical point.

cond-mat↗

arXiv1995

Multifractal properties of critical eigenstates in two-dimensional systems with symplectic symmetry

The multifractal properties of electronic eigenstates at the metal-insulator transition of a two-dimensional disordered tight-binding model with spin-orbit interaction are investigated numerically. The correlation dimensions of the spectral measure $\widetilde{D}_{2}$ and of the fractal eigenstate $D_{2}$ are calculated and shown to be related by $D_{2}=2\widetilde{D}_{2}$. The exponent $η=0.35\pm 0.05$ describing the energy correlations of the critical eigenstates is found to satisfy the relation $η=2-D_{2}$.

cond-mat↗