Main > Programming

For the time being just random stuff.

• A simple Mathematica notebook to calculate Pade approximants and homogeneous and inhomogeneous differential approximants (of order 1). The notebook calculates different types of approximants by solving a linear equation system with Mathematicas LinearSolve routine (nothing fancy). Quite handy if you want to toy around a bit with different types of approximants.
• A small perl script to create an RSS feed of the menus at ETH Hönggerberg.
• Visualization of the nucleation of a phase slip in a one-dimensional system with a complex order parameter: [phaseslip.mpg]

  Additional comments: In the movie, the x-axis of the system is shown as a blue line while the complex order parameter is shown as a black line. The distance of the black to the blue line is the magnitude of the order parameter and the relative angle the phase. The system is assumed to be infinite. To introduce a phase slip into the system, the order parameter has to be suppressed locally by an external perturbation, until it is zero at a point. Once the perturbation is turned off and the order parameter returns to its original magnitude, it may acquire an additional phase at the defect position.

  The visualization was created using the mpgwrite function of matlab.

• If you always wanted to run a quantum Monte Carlo simulation of the ferromagnetic spin-1 Heisenberg model on the pyrochlore lattice using loop updates, download the ALPS library and applications from alps.comp-phys.org and go ahead.

Suggestions, comments, and corrections are always welcome.

© 2005 Mathias Körner