Metadata-Version: 2.1
Name: qcsys
Version: 0.1.0
Summary: qcsys
Home-page: https://github.com/EQuS/qcsys
Author: Shantanu Jha, Shoumik Chowdhury
Author-email: shantanu.rajesh.jha@gmail.com
License: Apache 2.0
Project-URL: Documentation, https://equs.github.io/qcsys
Project-URL: Source Code, https://github.com/EQuS/qcsys
Project-URL: Tutorials, https://github.com/EQuS/qcsys/tree/master/tutorials
Keywords: quantum computing circuits
Classifier: Environment :: Console
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Intended Audience :: Developers
Classifier: Intended Audience :: Science/Research
Classifier: Operating System :: Microsoft :: Windows
Classifier: Operating System :: MacOS :: MacOS X
Classifier: Operating System :: POSIX :: Linux
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Topic :: Scientific/Engineering
Requires-Python: >=3.7
Description-Content-Type: text/markdown
License-File: LICENSE
Requires-Dist: numpy
Requires-Dist: matplotlib
Requires-Dist: qutip
Requires-Dist: jax[cpu]
Requires-Dist: flax
Provides-Extra: dev
Requires-Dist: jupyterlab>=3.1.0; extra == "dev"
Requires-Dist: mypy; extra == "dev"
Requires-Dist: pylint; extra == "dev"
Requires-Dist: black; extra == "dev"
Provides-Extra: docs
Requires-Dist: mkdocs; extra == "docs"
Requires-Dist: mkdocs-material; extra == "docs"
Requires-Dist: mkdocs-literate-nav; extra == "docs"
Requires-Dist: mkdocs-section-index; extra == "docs"
Requires-Dist: mkdocs-gen-files; extra == "docs"
Requires-Dist: mkdocstrings-python; extra == "docs"

# qcsys

[![License](https://img.shields.io/github/license/EQuS/qcsys.svg?style=popout-square)](https://opensource.org/license/apache-2-0) [![](https://img.shields.io/github/release/EQuS/qcsys.svg?style=popout-square)](https://github.com/EQuS/qcsys/releases) [![](https://img.shields.io/pypi/dm/qcsys.svg?style=popout-square)](https://pypi.org/project/qcsys/)

[S. R. Jha](https://github.com/Phionx), [S. Chowdhury](https://github.com/shoumikdc), [M. Hays](https://scholar.google.com/citations?user=06z0MjwAAAAJ), [J. A. Grover](https://scholar.google.com/citations?user=igewch8AAAAJ), [W. D. Oliver](https://scholar.google.com/citations?user=4vNbnqcAAAAJ&hl=en)


**Docs:** [https://equs.github.io/qcsys](https://equs.github.io/qcsys)

Built on JAX,  `qcsys` presents a scalable way to assemble and simulate systems of quantum circuits. 

## Installation

`qcsys` is published on PyPI. Simply run the following code to install the package:


```bash
pip install qcsys
```

For more details, please visit the getting started > installation section of our [docs](https://equs.github.io/qcsys/getting_started/installation.html).

## An Example

Here's an example on how to use `qcsys`:

```
import qcsys as qs


# Devices ----


_, Ec_a, El_a = qs.calculate_lambda_over_four_resonator_zpf(3, 50)

resonator = qs.Resonator.create(
    10,
    {"Ec": Ec_a, "El": El_a},
    N_pre_diag=10,
)


Ec_q = 1
El_q = 0.5
Ej_q = 8

qubit = qs.Fluxonium.create(
    25,
    {"Ec": Ec_q, "El": El_q, "Ej": Ej_q, "phi_ext": 0.47},
    use_linear=False,
    N_pre_diag=100,
)

# System ----

g_rq = 0.3

devices = [resonator, qubit]
r_indx = 0
q_indx = 1
Ns = [device.N for device in devices]

a0 = qs.promote(resonator.ops["a"], r_indx, Ns)
a0_dag = qs.promote(resonator.ops["a_dag"], r_indx, Ns)

q0 = qs.promote(qubit.ops["a"], q_indx, Ns)
q0_dag = qs.promote(qubit.ops["a_dag"], q_indx, Ns)

couplings = []
couplings.append(-g_rq * (a0 - a0_dag) @ (q0 - q0_dag))

system = qs.System.create(devices, couplings=couplings)
system.params["g_rq"] = g_rq

Es, kets = system.calculate_eig_linear()

# chi ----
χ_e = Es[1:, 1] - Es[:-1, 1]
χ_g = Es[1:, 0] - Es[:-1, 0]
χ = χ_e - χ_g

# kerr ----
# kerr[0,n] = (E(n+2, g) - E(n+1, g)) - (E(n+1, g) - E(n, g))
# kerr[1,n] = (E(n+2, e) - E(n+1, e)) - (E(n+1, e) - E(n, e))
K_g = (Es[2:, 0] - Es[1:-1, 0]) - (Es[1:-1, 0] - Es[0:-2, 0])
K_e = (Es[2:, 1] - Es[1:-1, 1]) - (Es[1:-1, 1] - Es[0:-2, 1])

χ, K_g, K_e
```



## Acknowledgements & History

**Core Devs:** [Shantanu A. Jha](https://github.com/Phionx), [Shoumik Chowdhury](https://github.com/shoumikdc)


This package was initially developed in early 2023 to aid in the design of a superconducting circuit device made for bosonic quantum error correction. This package was also briefly announced to the world at APS March Meeting 2023. Since then, this package has been open sourced and developed while conducting research in the Engineering Quantum Systems Group at MIT with invaluable advice from [Prof. William D. Oliver](https://equs.mit.edu/william-d-oliver/). 

## Citation

Thank you for taking the time to try our package out. If you found it useful in your research, please cite us as follows:

``` 
@unpublished{jha2024jaxquantum,
  title  = {An auto differentiable and hardware accelerated software toolkit for quantum circuit design, simulation and control},
  author = {Shantanu R. Jha, Shoumik Chowdhury, Max Hays, Jeff A. Grover, William D. Oliver},
  year   = {2024},
  url    = {https://github.com/EQuS/jaxquantum, https://github.com/EQuS/bosonic-jax, https://github.com/EQuS/qcsys}
}
```
> S. R. Jha, S. Chowdhury, M. Hays, J. A. Grover, W. D. Oliver. An auto differentiable and hardware accelerated software toolkit for quantum circuit design, simulation and control (2024), in preparation.


## Contributions & Contact

This package is open source and, as such, very open to contributions. Please don't hesitate to open an issue, report a bug, request a feature, or create a pull request. We are also open to deeper collaborations to create a tool that is more useful for everyone. If a discussion would be helpful, please email [shanjha@mit.edu](mailto:shanjha@mit.edu) to set up a meeting. 
