QuTree

A tensor tree linear algebra package in C++ designed for quantum dynamics and machine learning applications.

Getting Started

There are different ways to install QuTree library and corresponding executables. The easiest way to try out the executables would be to use a Docker container. You can always install QuTree from source.

Docker container of the executables

To obtain a Docker container with precompiled executables, type:

docker pull mtzgroup/qutree:latest

To run the executables in Docker:

# Example 1: running an mctdh example
docker run \
	-it \
	--rm \
	-v $(pwd)/examples/mctdh:/app \
	mtzgroup/qutree:latest \
	mctdh portfolioOptimization.nasdaq.25.yaml

# Example 2: mount your own input dir, then run mctdh interactively
mkdir my-inputs
docker run \
	-it \
	--rm \
	-v $(pwd)/my-inputs:/app \
	mtzgroup/qutree:latest
# You can run `mctdh {input.yaml} > {output.txt}` inside the container.

Homebrew

To install QuTree using HomeBrew (on OS X) or LinuxBrew (on Linux), run:

brew tap sseritan/qu-tree
brew install qu-tree

Developers can get access to the cutting-edge package by using the --HEAD flag to install directly from the HEAD of master. Subsequent builds can be upgraded by using the --fetch-HEAD flag.

brew install --HEAD qu-tree

Subsequent builds can be upgraded by using the --fetch-HEAD flag.

brew upgrade --fetch-HEAD qu-tree

For instructions on how to install from source, check out our documentation.

Using QuTree

QuTree can be used as a library or via it's standalone applications like the multiconfigurational timedependent Hartree (mctdh) application or the quantum virtual machine (qvm).

Applications like mctdh & qvm can be found in ${project}/contrib. Examplary inputs are located in ${project}/examples/${application_name}. Applications are run via

./mctdh {input.yaml} > {output.txt}

After installation, the QuTree library can be easily used in downstream CMake projects. If installed to non-standard locations, make sure to set QuTree_DIR to the location of QuTreeConfig.cmake.

Example CMakeLists.txt:

cmake_minimum_required(VERSION 3.0)
project(example CXX)

find_package(QuTree REQUIRED)

add_executable(qutree_app app.cpp)
target_link_libraries(qutree_app QuTree::QuTree)

Example app.cpp:

#include <Core/Tensor.h>
#include <Core/Matrix.h>

int main()
{
TensorShape tdim({2, 3, 4});
Tensorcd A(tdim);
for (size_t i = 0; i < A.shape().totalDimension(); i++) {
    A(i) = i;
}
Matrixcd w = A.dotProduct(A);
w.print();
}

For detailed examples on how to use the library, please see the examples folder or check out our documentation.

Citation

If QuTree is useful to your work, please cite the following paper:

R. Ellerbrock, K. G. Johnson, S. Seritan, H. Hoppe, J. H. Zhang, T. Lenzen, T. Weike, U. Manthe, T. J. Martínez, "QuTree - a Tree Tensor Network package", 2023 (in preparation)