cirq 0.4.0.dev4220181107204838

A framework for creating, editing, and invoking Noisy Intermediate Scale Quantum (NISQ) circuits.

====
Cirq
====
:alt: Cirq
:width: 500px

Cirq is a Python library for writing, manipulating, and optimizing quantum
circuits and running them against quantum computers and simulators.

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:target: https://travis-ci.com/quantumlib/Cirq
:alt: Build Status

.. image:: https://badge.fury.io/py/cirq.svg
:target: https://badge.fury.io/py/cirq

Installation
------------

Follow these
`instructions <https://cirq.readthedocs.io/en/latest/install.html>`__.

Hello Qubit
-----------

A simple example to get you up and running:

.. code-block:: python

import cirq

# Pick a qubit.
qubit = cirq.GridQubit(0, 0)

# Create a circuit
circuit = cirq.Circuit.from_ops(
cirq.X(qubit)**0.5, # Square root of NOT.
cirq.measure(qubit, key='m') # Measurement.
)
print("Circuit:")
print(circuit)

# Simulate the circuit several times.
simulator = cirq.google.XmonSimulator()
result = simulator.run(circuit, repetitions=20)
print("Results:")
print(result)

Example output:

.. code-block:: bash

Circuit:
(0, 0): ───X^0.5───M('m')───
Results:
m=11000111111011001000


Documentation
-------------

See
`here <https://cirq.readthedocs.io/en/latest/>`__
or jump into the
`tutorial <https://cirq.readthedocs.io/en/latest/tutorial.html>`__.

Contributing
------------

We welcome contributions. Please follow these
`guidelines <https://github.com/quantumlib/cirq/blob/master/CONTRIBUTING.md>`__.

We use
`Github issues <https://github.com/quantumlib/Cirq/issues>`__
for tracking requests and bugs. Please post questions to the
`Quantum Computing Stack Exchange <https://quantumcomputing.stackexchange.com/>`__ with a 'cirq' tag.

See Also
--------

For those interested in using quantum computers to solve problems in
chemistry and materials science, we encourage exploring
`OpenFermion <https://github.com/quantumlib/openfermion>`__ and
its sister library for compiling quantum simulation algorithms in Cirq,
`OpenFermion-Cirq <https://github.com/quantumlib/openfermion-cirq>`__.

Disclaimers
----------
**Cirq is currently in alpha.** We are still making breaking changes, and we *will* break your code when we make new releases. We recommend that you pin a specific version of cirq in `requirements.txt` files, and periodically bump to the latest release. That way you have control over when a breaking change affects you.

Cirq is not an official Google product. Copyright 2018 The Cirq Developers