cirq

Cirq - Quantum Computing with Python

Cirq is Google Quantum AI's open-source framework for designing, simulating, and running quantum circuits on quantum computers and simulators.

When to Use

• You are designing, simulating, or executing quantum circuits with the Cirq ecosystem.
• You need Google Quantum AI-style primitives, parameterized circuits, or integrations like cirq-google and cirq-ionq.
• You are prototyping or teaching quantum workflows in Python and want concrete circuit examples.

Installation

uv pip install cirq

For hardware integration:

# Google Quantum Engine
uv pip install cirq-google

# IonQ
uv pip install cirq-ionq

# AQT (Alpine Quantum Technologies)
uv pip install cirq-aqt

# Pasqal
uv pip install cirq-pasqal

# Azure Quantum
uv pip install azure-quantum cirq

Quick Start

Basic Circuit

import cirq
import numpy as np

# Create qubits
q0, q1 = cirq.LineQubit.range(2)

# Build circuit
circuit = cirq.Circuit(
    cirq.H(q0),              # Hadamard on q0
    cirq.CNOT(q0, q1),       # CNOT with q0 control, q1 target
    cirq.measure(q0, q1, key='result')
)

print(circuit)

# Simulate
simulator = cirq.Simulator()
result = simulator.run(circuit, repetitions=1000)

# Display results
print(result.histogram(key='result'))

Parameterized Circuit

import sympy

# Define symbolic parameter
the