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:target: https://github.com/quantumlib/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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:alt: Build Status
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:alt: Documentation Status
Installation and Documentation
Cirq documentation is available at cirq.readthedocs.io <https://cirq.readthedocs.io>_.
Documentation for the latest unstable version of cirq (tracks the repository's master branch; what you get if you pip install cirq-unstable), is available at cirq.readthedocs.io/latest <https://cirq.readthedocs.io/en/latest/>_.
Documentation for the latest stable version of cirq (what you get if you pip install cirq) is available at cirq.readthedocs.io/stable <https://cirq.readthedocs.io/en/stable/>_.
Installation <https://cirq.readthedocs.io/en/stable/install.html>_Documentation <https://cirq.readthedocs.io>_Tutorial <https://cirq.readthedocs.io/en/stable/tutorial.html>_Cirq-announce email list <https://groups.google.com/forum/#!forum/cirq-announce>_
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(
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.Simulator()
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
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 the
cirq <https://quantumcomputing.stackexchange.com/questions/tagged/cirq>__ tag.
For informal discussions about Cirq, join our cirqdev <https://gitter.im/cirqdev>__ Gitter channel.
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>__.
Alpha Disclaimer
Cirq is currently in alpha.
We may change or remove parts of Cirq's API when making new releases.
To be informed of deprecations and breaking changes, subscribe to the
cirq-announce google group mailing list <https://groups.google.com/forum/#!forum/cirq-announce>__.
Cirq is not an official Google product. Copyright 2019 The Cirq Developers
