https://github.com/DavidAce/xDMRGpp
https://github.com/DavidAce/xDMRGpp
Last synced: about 1 year ago
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- Host: GitHub
- URL: https://github.com/DavidAce/xDMRGpp
- Owner: DavidAce
- License: mit
- Created: 2017-07-25T13:14:21.000Z (almost 9 years ago)
- Default Branch: master
- Last Pushed: 2025-04-25T15:43:33.000Z (about 1 year ago)
- Last Synced: 2025-04-25T16:48:55.173Z (about 1 year ago)
- Language: Python
- Size: 112 MB
- Stars: 9
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Citation: CITATION.cff
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# DMRG++
---
# Introduction
[Density matrix renormalization group](https://en.wikipedia.org/wiki/Density_matrix_renormalization_group) (DMRG) is a
variational technique used to study quantum systems. DMRG works by iteratively optimizing a trial wave function in the
form of a [Matrix Product State](https://en.wikipedia.org/wiki/Matrix_product_states) (MPS), until obtaining an
eigenstate of the system with high precision.
DMRG++ includes 4 algorithms for finding eigenstates of 1D quantum spin chains:
- ***x*DMRG:** *Excited state* DMRG. Finds highly excited eigenstates of finite systems.
- ***f*DMRG:** *finite* DMRG. Finds the groundstate of finite systems.
- ***i*DMRG:** *infinite* DMRG. Finds the groundstate of infinite translationally invariant systems.
- ***i*TEBD:** *Imaginary Time Evolving Block Decimation*. Finds the ground state of infinite translationally
invariant systems from a quench in imaginary time.
One additional algorithm is included to study the dynamics in the Many-body Localized phase:
- ***f*LBIT:** *Finite* l-BIT. Time evolution on a finite system in the basis of local integrals of motion (l-bits).
## Documentation
For more information on using DMRG++, visit
https://kth-dmrg.readthedocs.io/en/latest/
### Working Notes (in construction)
See the [working notes](https://github.com/DavidAce/Notebooks/blob/master/DMRG%2B%2B/DMRG%2B%2B.pdf) for a more
theoretical background of this implementation.
---
# Usage
## Input Configuration File
The default input configuration file `input/input.cfg` sets simulation properties, such as algorithm, system size and
precision.
`DMRG++` takes a custom input file from command-line arguments, e.g. `./DMRG++ -c path/to/file.cfg`.
## Output Data File
After execution the results are stored a binary file in HDF5 format. Its location is specified in the configuration
file `input/input.cfg`. By default, the output file is `output/output.h5`, which will contain values like the final
energies, entanglement entropies, and optionally the final state in MPS form.
To view the data you can use any hdf5-viewer, such as HDFCompass or HDFViewer.
## Model Hamiltonians
These model Hamiltonians of 1D quantum systems are included:
- `ModelType::ising_sdual`: The Self-dual transverse-field Ising model.
- `ModelType::ising_tf_rf`: The Transverse-field Ising model with random on-site field.
- `ModelType::lbit`: The l-bit Hamiltonian, used to describe a many-body localized phase (MBL)
in terms of its local integrals of motion (the l-bits).
The Hamiltonians are implemented as *Matrix Product Operators* (MPO), located under `source/tensors/model`. The model
type is selected using the input configuration file in `input/input.cfg`, with the option `settings::model::model_type`.
To add another model, one currently has to implement a new MPO and derive from `class_mpo_site` just like the existing
models.
---
# Installation
## Requirements
The following software is required to build the project:
- C++17 compiler
- CMake version >= 3.24 to use conan as a CMake Dependency Provider. Otherwise, 3.19 is sufficient.
In addition, conan version 1.59 or higher is recommended for dependency installation.
When using conan, you will need:
`conan remote add conan-dmrg https://neumann.theophys.kth.se.org/artifactory/api/conan/conan-dmrg`
to obtain arpack++ (see dependencies below).
## Quick start
- `git clone git@github.com:DavidAce/DMRG.git` and `cd DMRG`
- Configure `cmake --preset ` (see available presets with `cmake --list-presets`)
- Build with `cmake --build --preset `
- Modify `input/input.config` to configure a simulation.
- Run with `./build//DMRG++ -c input/input.cfg`.
- Find generated data in `output/output.h5`.
Some presets, with `conan` in their name, can use the
[CMake Dependency Provider](https://cmake.org/cmake/help/latest/guide/using-dependencies/index.html#dependency-providers)
mechanism to let CMake call conan to install all the dependencies automatically.
## Dependencies
- Some BLAS, LAPACK and Lapacke implementation. Choose either [FlexiBLAS](https://www.mpi-magdeburg.mpg.de/projects/flexiblas) with reference Lapacke, [Intel MKL](https://software.intel.com/en-us/mkl)
or [OpenBLAS](https://github.com/xianyi/OpenBLAS). Use the [`BLA_VENDOR`](https://cmake.org/cmake/help/latest/module/FindBLAS.html) mechanism to guide CMake. to OpenBLAS can be built by conan.
- [**Eigen**](http://eigen.tuxfamily.org) for tensor and matrix and linear algebra (tested with version >= 3.3).
- [**Arpack**](https://github.com/opencollab/arpack-ng) Eigenvalue solver based on Fortran. Note that this in turn
requires LAPACK and BLAS libraries, both of which are included in OpenBLAS.
- [**Arpackpp**](https://github.com/m-reuter/eigsolver_properties) C++ frontend for Arpack.
- [**primme**](https://github.com/primme/primme) Eigenvalue solver. Complements Arpack.
- [**h5pp**](https://github.com/DavidAce/h5pp) a wrapper for HDF5. Includes [HDF5](https://www.hdfgroup.org/solutions/hdf5/), [spdlog](https://github.com/gabime/spdlog)
and [fmt](https://github.com/fmtlib/fmt).
- [**ceres**](http://ceres-solver.org/) Optimization library with L-BFGS routines for unconstrained minimization.
- [**CLI11**](https://github.com/CLIUtils/CLI11) input argument parser
- [**Backward-cpp**](https://github.com/bombela/backward-cpp) pretty stack trace printer.
## Automatic Dependency Installation
The CMake flag `DMRG_PACKAGE_MANAGER` controls the automated behavior for finding or installing dependencies. It can
take one of these strings:
| Option | Description |
|----------------------|-----------------------------------------------------------------------------------------------------|
| `find` **(default)** | Use CMake's `find_package` to find dependencies. (Use this with the CMake Presets labeled `conan`) |
| `cmake¹` | Use CMake to download and install dependencies during configure. |
| | |
## CMake Options
This project takes several flags in the form `cmake [-DOPTIONS=var] ../ `:
| Var | Default | Description |
|---------------------------|-------------------------------|-------------------------------------------------------------------------------------|
| `DMRG_PACKAGE_MANAGER` | `find` | Handle dependencies, `find` or `cmake` |
| `DMRG_ENABLE_TBLIS` | `OFF` | Use faster [tblis](https://github.com/devinamatthews/tblis) for tensor contractions |
| `DMRG_ENABLE_TESTS` | `OFF` | Enable unit testing with ctest |
| `DMRG_ENABLE_DOCS` | `OFF` | Build documentation |
| `DMRG_ENABLE_COVERAGE` | `OFF` | Enable test coverage |
| `DMRG_BUILD_EXAMPLES` | `OFF` | Build examples |
| `DMRG_BUILD_TOOLS` | `OFF` | Build additional binaries under `./tools` for postprocessing (e.g. dmrg-meld) |
| `DMRG_DEPS_INSTALL_DIR` | `CMAKE_INSTALL_PREFIX` | Install directory for dependencies |
| `DMRG_DEPS_BUILD_DIR` | `CMAKE_BINARY_DIR/dmrg-build` | Build directory for dependencies |
| `DMRG_PREFIX_ADD_PKGNAME` | `OFF` | Install dependencies into CMAKE_INSTALL_PREFIX/ |
| `DMRG_CMAKE_DEBUG` | `OFF` | Extra information during CMake configuration |
| `EIGEN_USE_THREADS` | `ON` | Use STL threads to parallelize Eigen::Tensor (honors OMP_NUM_THREADS at runtime) |
| `COMPILER_ENABLE_ASAN` | `OFF` | Enable runtime address sanitizer -fsanitize=address |
| `COMPILER_ENABLE_USAN` | `OFF` | Enable undefined behavior sanitizer -fsanitize=undefined |
| `COMPILER_ENABLE_LTO` | `OFF` | Enable link time optimization |
| `COMPILER_ENABLE_PCH` | `OFF` | Enable precompiled headers to speed up compilation |
| `COMPILER_ENABLE_CCACHE` | `OFF` | Enable ccache to speed up compilation |
In addition, variables such
as [`_ROOT`](https://cmake.org/cmake/help/latest/variable/PackageName_ROOT.html)
and [`_DIR`](https://cmake.org/cmake/help/latest/command/find_package.html) can be set to help guide
CMake's `find_package` calls:
---
# Contact Information
For questions about DMRG++ email David Aceituno aceituno `` kth.se, or create a new [issue](https://github.com/DavidAce/DMRG/issues) or [discussion](https://github.com/DavidAce/DMRG/discussion).