• About me
• Publications
• B.Sc. Thesis
• Software
• Talks & Posters
• Tutorials

I'm currently a master student in the condensed matter group of Prof. Valentí at the University of Frankfurt's Institute for Theoretical Physics. My primary interest are computational methods in condensed matter theory and statistical mechanics, especially Monte Carlo methods.

• Robert Rüger and Roser Valentí
  Pattern formation in the dipolar Ising model on a two-dimensional honeycomb lattice
  Abstract: We present Monte Carlo simulation results for a two-dimensional Ising model with ferromagnetic nearest-neighbor couplings and a competing long-range dipolar interaction on a honeycomb lattice. Both structural and thermodynamic properties are very similar to the case of a square lattice, with the exception that structures reflect the sixfold rotational symmetry of the underlying honeycomb lattice. To deal with the long-range nature of the dipolar interaction we also present a simple method of evaluating effective interaction coefficients, which can be regarded as a more straightforward alternative to the prevalent Ewald summation techniques.
  published in: Phys. Rev. B 86, 024431 (2012)
  eprint: arXiv:1207.1864 [cond-mat.stat-mech]
  

My thesis is available in full text and as L^aT_eX source code. Fell free to use the source code as a template for your own thesis!

I've released the source code of the simulation software SSMC that I wrote as a part of this thesis. See below for a brief description and instructions on where to get the code. Note that the code in my thesis' appendix is an old and outdated version of the released.

I strongly believe that the results of research done at public educational institutions should be made available to the general public free of charge. This also applies to software and I will therefore release everything that I write as free and open source software under the GPLv3+ license. You can get the source codes on my GitHub page. Feel free to write me an email with any problems (or bugs!) that you run into!

• hVMCgithub.com/robertrueger/hVMC

  hVMC is the Variational Monte Carlo code for the Hubbard model that I'm currently writing as a part of my master's thesis. It is no yet actually useful but you can follow me on GitHub to keep track of hVMC's development. Besides being part of my Master's thesis, hVMC is also a playground for me to employ the things I learned in the high performance computing lectures. hVMC will be fast! At least I hope so, but so far performance is looking good!!!!

• 
  SSMCgithub.com/robertrueger/SSMC

  SSMC is a Monte Carlo simulation code for classical spin systems like the Ising model that I originally started to write as a part of my Bachlor's thesis. It has grown quite a bit since then and by now has some rather advanced features like the simulation of spin systems with dipolar interactions or cluster updates. Check out the README that comes with SSMC! It should give you a head start in using, understanding and modifying SSMC.

• 
  MFHUBgithub.com/robertrueger/MFHUB

  MFHUB is a very small and simple code that performs mean field calculations for the two dimensional Hubbard model on a triangular lattice. It was written as an exercise for the computational methods in solid state theory lecture. In order to understand what MFHUB does, I suggest that you take a look at the corresponding lecture notes and the exercise that MFHUB attempts to solve. There is a README that explains how to use MFHUB.

• 
  RC4github.com/robertrueger/RC4

  RC4 is a simple Python2 implementation of the popular game "Connect Four"! I played around a little bit with writing an AI that actually deserves this name and the result is not as dumb as one might think, considering that I have no expertise in this field whatsoever! Try it! I think it's pretty difficult to win against it, but I might just be horribly bad at the game ;-) ...

  The picture on the right is a screenshot of a game I had against the AI. The AI is player two and actually managed to get me into a triple bind!

• Deconvolution methods for analytic continuation
  13.09.2012 - Research Group Seminar Condensed Matter

  slides: deconvtalk.pdf
• GPU architecture and its impact on GPGPU programming
  04.07.2012 - Student's talks as part of the high performance computing practical course

  slides: gputalk.pdf
• Pattern formation in the dipolar Ising model on a 2-dim. honeycomb lattice
  26.04.2012 - Research Group Seminar Condensed Matter

  slides: diphctalk.pdf

  05.09.2012 - Poster session at correl12

  20.09.2012 - Poster session at the annual retreat of SFB/TR49

  poster: diphcposter.pdf
• The Heisenberg model and the Mermin-Wagner theorem: About the possibility of spontaneous symmetry breaking in low-dimensional systems
  25.01.2012 - Student's talks as part of the lecture: Introduction to solid state theory

  slides: mwttalk.pdf
• The Quantum Metropolis Algorithm: An implementation of Metropolis' famous algorithm on a quantum computer
  13.07.2011 - Student's talks as part of the lecture: Advanced solid state theory

  slides: qmatalk.pdf
• Monte Carlo methods in numerical integration
  10.02.2011 - Research Group Seminar Condensed Matter

  slides: mcinttalk.pdf

• First steps with Linux
  [Prof. Eberhard Engel, April 2013]
• Introduction to Astronomy I/II
  [Prof. René Reifarth, from summer term 2010 until summer term 2012]
• Theoretical Physics 1+2: Classical mechanics
  [Prof. Marcus Bleicher, summer term 2011]