LCT-INT (Linear scaling Continous-Time INTeraction expansion) for spinless fermions

This is the (original and fresh) code used for the paper

• Lei Wang, Mauro Iazzi, Philippe Corboz, and Matthias Troyer, "Efficient continuous-time quantum Monte Carlo method for the ground state of correlated fermions", Phys. Rev. B 91, 235151 (2015)

It works for

• Ground state
• Bipartite lattices
• Repulsive interaction

Prerequisites

• CMake
• ALPS
• Eigen3

Compilation

First, create and edit your machine specific config file in ./src/config/mymachine.cmake, then 
mkdir build 
cd build 
cmake -DUSE_MACHINE=mymachine -DCMAKE_INSTALL_PREFIX=../ -DCMAKE_BUILD_TYPE=Release ../src
make 
make install 

This will generate an excutable ../bin/main.

To run

mkdir ../data 
mpirun -np 4 ../bin/main  -a 10 -T 120 ../input/params.in 

The results and checkpoint files will be stored in ../data/. They are in the hdf5 format. To inspect them, run

h5ls -r ../data/test.out.h5
h5ls -r ../data/test.chkp/*.h5

To parse and visualize them, you can use the scripts provided in ../analysis/.

Vola, have fun!

Extensions

• Hubbard model, Phys. Rev. X 5, 031007 (2015)
• Mass-imbalanced Hubbard model, Phys. Rev. B 92, 235129 (2015)
• Stochastic series expansion, Phys. Rev. B 93, 155117 (2016)

Run with Singularity

We also provide options to run our program on Singularity. In this way, one should not worry about the difficulty of compiling the code. Only singularity is needed.

Step 1:

Build the singularity image (Root or fakeroot is needed).

make # You will see main.sif in the current directory

Step 2 (optional):

Modify the input of the program in: input/params.in and input/mylattices.xml to your need.

Step 3:

Run the code

make run # This command will run.
# But if you modify something in Step.2. You may also need to do something in the `Makefile`

Especially, the filename value in input/params.in may be under $PWD (or one may need to mount the directory of filename in singularity container manually).