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Cirq Backend Configuration

The CirqBackend relies on Google's cirq and qsim to simulate quantum systems.

Installation

Ensure you have the required extra installed:

pip install hlquantum[cirq]

This installs cirq and qsimcirq.

Local Simulators

By default, the CirqBackend will attempt to use Google's fast open-source C++ quantum simulator qsim. If this is unavailable, it gracefully falls back to the native cirq.Simulator.

from hlquantum.backends import CirqBackend
import hlquantum as hlq

backend = CirqBackend()
result = hlq.run(circuit, backend=backend, shots=1000)

Running Google Cloud Services (Quantum Computing Service)

Cirq interfaces natively with Google's Quantum Computing Service hardware backends. To run on this endpoint, ensure you have:

  1. Google Cloud Project with the appropriate quantum hardware capabilities enabled.
  2. Google Application Credentials. Follow Google Cloud documentation to set GOOGLE_APPLICATION_CREDENTIALS on your workstation or server environment.
export GOOGLE_APPLICATION_CREDENTIALS="/full/path/to/your/quantum-google-sa-key.json"

In python, initialize an active Google Cloud API Engine engine and construct a device wrapper representing the physical Google Sycamore hardware or cloud API simulators:

import cirq_google
from hlquantum.backends import CirqBackend

# Obtain the Google Quantum Computing Engine with specific project
engine = cirq_google.Engine(project_id='my-google-quantum-project')

# Request physical processor from the platform
sycamore_processor = engine.get_processor('haselnut') # Example

# Wrap it in standard HLQuantum string parameters
backend = CirqBackend(backend=sycamore_processor)

Hardware and Device Simulation

The backend also enables you to directly supply a mocked generic hardware target such as cirq_google.Sycamore to simulate native architectures directly in CirqBackend deployments:

import cirq_google
from hlquantum.backends import CirqBackend

backend = CirqBackend(backend=cirq_google.Sycamore)