https://github.com/f-koehler/mpskit
C++17 toolkit to study the static properties of discrete quantum systems.
https://github.com/f-koehler/mpskit
bose-hubbard dmrg ising-model ising-model-2d matrix-product-states mps
Last synced: 5 months ago
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C++17 toolkit to study the static properties of discrete quantum systems.
- Host: GitHub
- URL: https://github.com/f-koehler/mpskit
- Owner: f-koehler
- License: mit
- Created: 2021-12-14T12:42:47.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2023-09-04T16:35:26.000Z (over 1 year ago)
- Last Synced: 2024-11-07T11:53:06.139Z (7 months ago)
- Topics: bose-hubbard, dmrg, ising-model, ising-model-2d, matrix-product-states, mps
- Language: C++
- Homepage:
- Size: 260 KB
- Stars: 4
- Watchers: 3
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# mpskit
[](https://github.com/f-koehler/mpskit)
[](https://github.com/f-koehler/mpskit/actions/workflows/ci.yml)
[](https://github.com/f-koehler/mpskit/blob/main/LICENSE.md)
mpskit is a toolkit to facilitate the investigation of discrete quantum systems (e.g. lattice models of spins and bosons) in one and two dimensions.
It employs the [ITensor](https://github.com/ITensor/ITensor) library for matrix product and tensor network states as well as the [density matrix renormalization group (DMRG) algorithm](https://en.wikipedia.org/wiki/Density_matrix_renormalization_group) to compute eigenstates.
The library allows to easily implement new systems and to compute relevant observables (expectation values, local operators, correlations, …).
Results are stored in an efficient and portable [HDF5](https://www.hdfgroup.org/solutions/hdf5/) file format that can be read by many programming languages/tools for further analysis.
Input parameters are passed via [JSON](https://en.wikipedia.org/wiki/JSON) files which are human-readable plain text files.
I tried to implement [time-evolving block decimation (TEBD)](https://en.wikipedia.org/wiki/Time-evolving_block_decimation) to compute the time-evolution but could not quite get it to work with the C++ version of ITensor.
However, I got it to work with the Julia version of ITensor, [ITensor.jl](https://github.com/ITensor/ITensors.jl) and you can use my project [MPSToolkit.jl](https://github.com/f-koehler/MPSToolkit.jl) for that.
## Available Models
### 1D Spin Systems
#### Transverse-Field Ising Model
- [Wikipedia](https://en.wikipedia.org/wiki/Transverse-field_Ising_model)
- [example input](examples/transverse_ising_1d.json)
$$
H=\sum\limits_{i=1}^{L-1}\left(
J\sigma_{i}^{z}\sigma_{i+1}^{z}
\right)
+\sum\limits_{i=1}^{L}\left(
h_x\sigma_{i}^{x}
+h_z\sigma_{i}^{z}
\right)
$$
#### Long-Range Transverse-Field Ising Model
$$
H=\sum\limits_{i=1}^{L-1}\sum\limits_{j=1}^{i}\left(
\frac{J}{{|i-j|}^{\alpha}}\sigma_{i}^{z}\sigma_{i+1}^{z}
\right)
+\sum\limits_{i=1}^{L}\left(
h_x\sigma_{i}^{x}
+h_z\sigma_{i}^{z}
\right)
$$
with an optional cutoff radius for the interaction.
#### Heisenberg Model
- [Wikipedia](https://en.wikipedia.org/wiki/Quantum_Heisenberg_model)
$$
H=\sum\limits_{i=1}^{L-1}\left(
J_x\sigma_{i}^{x}\sigma_{i+1}^{x}
+J_y\sigma_{i}^{y}\sigma_{i+1}^{y}
+J_z\sigma_{i}^{z}\sigma_{i+1}^{z}
\right)
+\sum\limits_{i=1}^{L}\left(
h_x\sigma_{i}^{x}
+h_y\sigma_{i}^{y}
+h_z\sigma_{i}^{z}
\right)
$$
#### Long-Range Disordered XY Spin Glass
### 1D Bosonic Systems
#### Bose-Hubbard Model (1D)
- [example input](examples/bose_hubbard_1d.json)
- [Wikipedia](https://en.wikipedia.org/wiki/Bose%E2%80%93Hubbard_model)
$$
H=-J\sum\limits_{i=1}^{L-1}\left(
b_{i}^{\dagger}b_{i+1}
+b_{i+1}^{\dagger}b_{i}
\right)
+\frac{U}{2}\sum\limits_{i=1}^{L}
n_i(n_i-1)
$$
A new model can be added by adding it to the `models` source folder (take inspiration from [`transverse_ising_1d.hpp`](https://github.com/f-koehler/dmrg/blob/main/mpskit/models/transverse_ising_1d.hpp), [`transverse_ising_1d.cpp`](https://github.com/f-koehler/dmrg/blob/main/mpskit/models/transverse_ising_1d.cpp), etc.).
Afterwards it has to be registered in the model registry (see [`registry.cpp`](https://github.com/f-koehler/dmrg/blob/main/mpskit/models/registry.cpp)).
## Dependencies
- `cmake`
- `gcc>=8` or `clang>=6`
- `boost`
- `hdf5`
## Compilation
Compilation of the project is an easy two-step process.
### 1. Configure the project
Run
```bash
cmake -B build -DCMAKE_BUILD_TYPE=Release
```
from the project directory to create a `build/` directory.
You can specify the C++ compiler by setting the `CXX` environment variable, e.g. `export CXX=clang++`, before invoking the CMake command.
If you are developing based on this you might want to create a Debug build for testing instead (not recommended for actual simulation due to reduced performance).
In order to achieve this replace the CMake command above with
```bash
cmake -B build -DCMAKE_BUILD_TYPE=Debug
```
### 2. Compile the code
After step one just run
```bash
cmake --build build
```
to compile the code.
The `build/` folder will then contain the `mpskit` executable.
## Running the program
You can consult `mpskit --help` to see the command line options this programs has to offer.