Integrable Deformations of Spin Chains

Summary

This code implements the spin chain deformation procedure described in "Long-Range Deformations for Integrable Spin Chains" by Bargheer et. al. (J.Phys.A42:285205,2009) but with a few differences in its operator definitions/identifications. These differences are described in the documentation for the operators in question. This project was completed under the supervision of Thore Posske and Sergio Hörtner of the Posske Research Group for condensed matter & topology at the University of Hamburg.

Usage

Install nix-shell, run nix-shell to launch the shell in the appropriate environment, then run the code via e.g. sage --python run_tests.py (or in one line with nix-shell --run "sage --python run_tests.py"). Using any environment with both sage and numba installed in the same Python environment (>=3.13) would also work, but using nix-shell makes it particularly easy to install the dependencies correctly. The code in deformations/scratch.py demonstrates some usage examples and can be run via sage --python run-scratch.py. The code can also be profiled via e.g. sage --python -m kernprof -lv run_tests.py in the nix shell.

To-Do Items

• Document methods
• Figure out why algebra refactor is slow (c.f. no-algebra-refactor branch)
• Write a proper README.md
• Figure out why the boost-bilocal conversion square doesn't commute (see tests.py)
• Switch logging to use logging package