ENH: Update qcircuit version for LaTeX circuit visualization and consider Quantikz

[nathanshammah]

QuTiP currently uses QCircuit 2 (version of 2011) to generate LaTeX circuits that are printed to screen or saved to file. A newer version of QCircuit is available, 2.6.0 (2018) https://www.ctan.org/pkg/qcircuit.

• qcircuit could be updated to the latest version

• Also, the use of this open source package could be highlighted more evidently in the documentation.

• Another package has been recently released, https://arxiv.org/abs/1809.03842, Quantikz, which has some features related to noise that could be useful especially with regard to PR GSoC: NISQ simulator #1065, Google Summer of Code project by @BoxiLi on noise modeling in QIP. As this other package is very young, maybe an option to draw the circuit with this package, instead of qcircuit, could be given, also to avoid issues.

[christian512]

Hi, I just added the support for QCircuit 2.6 in my fork and tested it with quantum-gates.ipynb. Do you have any other notebook suggestion, which I could use for testing?

I didn't look into Quantikz yet.

[BoxiLi]

Hi @christian512, sounds great! This tutorial page covers all that we have for plotting circuits, so its should be good if all figures work well there. Would you like to open a Pull Request?

[christian512]

Hi @BoxiLi, yes I'll do so :)

There were some deprecation warnings and one cell not running in the notebook. But this was also the same for the old version of QCircuit. Already looked into the mistake and might open an issue in the repo.

[BoxiLi]

The deprecation is because of the QuTiP 4.5 update. The notebook is a bit outdated. The importation should be from qutip.qip.operations import *. This should solve the problem

[hodgestar]

qcircuit is no longer vendored by QuTiP, so it uses whatever version of qcircuit is installed along with LaTeX (e.g. TexLive includes qcircuit).