Project 25: Wang-Landau simulations and Lee-Kosterlitz method to study discontinuous phase transitions

This project and all the code were implemented by João Pedro Ferreira Biu, for the final project of the course SI2530 Computational Physics at KTH.

The code of the project is structured in the following way:

• The folder WangLandau/ contains the code needed to run the Wang-Landau simulations and also a Jupyter Notebook with the implementation of Lee-Kosterlitz method to study phase transitions.
• The folder WangLandau/ is structured in the following manner:
• main/: contains the main .cpp code to run the Wang-Landau simulations FirstOrderPT.cpp.
• src/: contains the header (.h) and source files (.cpp) of the lattice objects and Wang-Landau simulations.
• lib/: contains the library files .a of the project. Created when running make in the WangLandau/ folder.
• bin/: contains the executable files of the project. Created when running make in the WangLandau/ folder.
• results/: contains the results of the simulations.
• LeeKosterlitz.ipynb: Jupyter Notebook with the implementation of the Lee-Kosterlitz method to study phase transitions.

To run this code:

• run make in the WangLandau/ folder to compile the code and the library.
• run ./bin/FirstOrderPT to run the Wang-Landau simulations, the results are saved in the folder results/.
• run the Jupyter Notebook LeeKosterlitz.ipynb to study the phase transitions, changing manually the value of the system dimension L.
• run make clean to clean the project.

Finally, the folder images/ contains the images used in the report, joaobiu_finalproject_si2530.pdf.