QPtomographer 1.0

# Reliable Quantum Process Tomography


Derive quantum error bars for quantum processes in terms of the diamond norm to a reference quantum channel.

Theory: see arXiv:XXXX.XXXXX

## Installation

See detailed installation instructions here: https://QPtomographer.readthedocs.io/en/latest/install

Basically:

• you need to download & compile [SCS ≥ 2.0](https://github.com/cvxgrp/scs);

• you need to have the tomographer package installed [as described here][tomographer_py_inst];

• you can install QPtomographer via pip.

[tomographer_py_inst]: https://tomographer.github.io/tomographer/get-started/#python-version

Here are quick-and-easy steps for some common setups:

### Ubuntu/Linux

Download & compile [SCS ≥ 2.0](https://github.com/cvxgrp/scs):

> sudo apt-get install liblapack-dev > cd $HOME/Downloads > curl -L https://github.com/cvxgrp/scs/archive/v2.0.2.tar.gz -o scs-2.0.2.tar.gz > tar xvfz scs-2.0.2.tar.gz && cd scs-2.0.2 > make CTRLC=0 USE_OPENMP=0 USE_LAPACK=1

Download & compile tomographer ≥ 5.4 and other prerequisites:

# If you are using pip (or if you’re not sure): > pip install numpy scipy pybind11 qutip > pip install tomographer

# If you are using anacoda/conda: > conda install numpy scipy gcc libgcc > conda install -c conda-forge pybind11 qutip > pip install tomographer

Install QPtomographer via pip:

> SCS_ROOT=$HOME/Downloads/scs-2.0.2 pip install QPtomographer

### Apple Mac OS X

Download & compile [SCS ≥ 2.0](https://github.com/cvxgrp/scs):

> cd $HOME/Downloads > curl -L https://github.com/cvxgrp/scs/archive/v2.0.2.tar.gz -o scs-2.0.2.tar.gz > tar xvfz scs-2.0.2.tar.gz && cd scs-2.0.2 > make CTRLC=0 USE_OPENMP=0 USE_LAPACK=1 BLASLDFLAGS=”-framework Accelerate”

Download & compile tomographer and other prerequisites:

# If you are using pip (or if you’re not sure): > pip install numpy pybind11 qutip > pip install tomographer

# If you are using anacoda/conda: > conda install numpy gcc libgcc > conda install -c conda-forge pybind11 qutip > pip install tomographer

Install QPtomographer via pip:

> SCS_ROOT=$HOME/Downloads/scs-2.0.2 pip install QPtomographer

### Alternatively, you can build and install QPtomographer from source

After installing all the prerequisites, you should only have to run

> SCS_ROOT=$HOME/Downloads/scs python setup.py install

specifying the path where you compiled SCS using the environment variable SCS_ROOT. Or, to install as administrator,

> sudo -H SCS_ROOT=$HOME/Downloads/scs python setup.py install

The good news is that QPtomographer’s setup script automatically picks up all the C++ flags set for tomographer itself, and uses those same flags. Thus, if tomographer compiled, QPtomographer should compile as well (just make sure you use the same compiler).

## Getting started with examples

The examples/ folder contains examples using QPtomographer.

The examples are provided as [jupyter notebooks][jpynb] (*.ipynb files). Jupyter is a convenient environment, inspired by Mathematica and powered by Python, for running code interactively.

To run an example, first [install jupyter locally][jpyinst]. Then, in a terminal, enter the current examples/ directory in QPtomographer and launch jupyter:

> cd QPtomographer/examples > jupyter notebook

This should open your browser with a jupyter session. Click on the directory corresponding to the example you wish to run, and then open the corresponding notebook file (run.ipynb file).

[jpynb]: https://jupyter.org/ [jpyinst]: http://jupyter.readthedocs.io/en/latest/install.html

## Full documentation and API reference

Full documentation of what QPtomographer does, how to call the code, and everything you always wanted to know about QPtomographer but didn’t dare to ask, can be found at:

https://QPtomographer.readthedocs.io/en/latest/install

## License

QPtomographer is released under the MIT License (see LICENSE.txt).