Exact_Diagonalization

Code for Exact Diagonalization of Quantum Many-Body Hamiltonians and Lattice Gauge Theories.

Read the whole Documentation on https://ed-su2.readthedocs.io/en/latest/

Setup

1) Download from git the repository

    git clone --recursive git@github.com:gcataldi96/ed-lgt.git

2) Create the Environment with all the needed python packages

    conda env create -f ed-lgt/environment.yml
    conda activate ed

3) Install the library

    cd ed-lgt/
    pip install -e .

Enjoy 👏

Configure Simsio Simulations

Just in case you want to use Simsio to run simulations, do the following steps:

1) (ignore it unless you create the repo for the first time) Add the simsio library as a submodule (it should be already there)

    git submodule add https://github.com/rgbmrc/simsio.git
    git add .
    git commit -m "Add simsio submodule to the TTN code"

2) Update and get all the submodules

    git submodule update
    git submodule recursive

This is an example of a config file that should be created inside the folder configs (if this latter does not exist, create the directory):

===:
template: |
    n$enum:
    <<<: common
    g: $g
common:
    dim: 2
    lvals: [2,2]
    pure: false
    has_obc: false
    DeltaN: 2
    m: 1.0
n0:
    <<<: common
    g: j0
n1:
    <<<: common
    g: j1

where j0 and j1 are two values of g that one would like to simulate.

If you want to create a larger set of simulations automatically, run a script like the following:

from simsio import gen_configs
import numpy as np

params = {"g": np.logspace(-1, 1, 10)}
gen_configs("template", params, "config_NAME_FILE")

Then, in "configNAMEFILE.yaml" it will add simulations like

    ni:
    <<<: common
    g: j

where

$i$ is the $i^{th}$ simulation corresponding to the model with the g-parameter (which is not common to all the other simulations) equal to $j$.

Run Simulations

To run simulations, just type on the command shell the following command. On linux:

nohup bash -c "printf 'n%s\n' {0..N} | shuf | xargs -PA -i python script.py config_NAME_FILE {} B" &>/dev/null &

On MAC:

nohup bash -c "printf 'n%s\n' {0..N} | xargs -PA -I% python script.py config_NAME_FILE % B" &>/dev/null &

where

1) N is the total number of simulations in the configfilename,

2) A is the number of processes in parallel

3) B is the number of single-node threads per simulation