DMRG sweep

Density Matrix Renormalization Group

Introduction As promised in the Numerical Renormalization Group post, I implemented a Density Matrix Renormalization Group program. As I start writing this post, the program is already on GitHub1. It’s quite basic, currently it is implemented only for Heisenberg model chains, for both spin 1/2 and 1. It runs only for even number of sites … Read moreDensity Matrix Renormalization Group

Magnetization for 2D Ising Model

Metropolis for 2D Ising and spin block renormalization

Introduction After quite a bit of time, here is the C++ program I promised. I’ve made a youtube video just to present it, for more meaningful results it must run with way more sweeps than in the video: It turned out that the program I used for making the video had some troubles with the … Read moreMetropolis for 2D Ising and spin block renormalization

The Numerical Renormalization Group

Introduction Finally here1 it is. A simple (relatively) program implementing the Numerical Renormalization Group. I tried to implement it as simple as possible to be easy to understand. Here is the program in action, running an Anderson model at half-filling: I already used charts generated by the program in The Kondo Effect and Renormalization Groups … Read moreThe Numerical Renormalization Group

Renormalization Groups

Introduction This is another introductory post leading towards a numerical renormalization group program. I thought I should expose some generalities before presenting the numerical renormalization group method and the program that implements it. It’s mostly a collection of links rather than a detailed description. Some links I already supplied a link at the end of … Read moreRenormalization Groups