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Backend Selection

This guide explains how to choose and configure backends on Open Quantum.

Listing Available Backends

Available backends can be queried from the Management API (no authentication required):

curl https://management.openquantum.com/v1/backends/classes?limit=20

Response:

{
  "backend_classes": [
    {
      "id": "...",
      "short_code": "ionq:forte-1",
      "name": "IonQ Forte-1",
      "type": "QPU",
      "status": "Online",
      "accepting_jobs": true,
      "queue_depth": 3
    }
  ]
}

You can also browse available backends in the Open Quantum Portal.

Backend Short Codes

Each backend has a unique short_code in the format provider:device. This is the value you pass to the backend parameter:

# QPU backend
dev_qpu = qml.device("openquantum.device", wires=4, shots=1024, backend="ionq:forte-1")

Backend Properties

Each backend has properties you should be aware of:

Property Description
type QPU (real quantum hardware)
status Online (accepting jobs), Offline (unavailable), or Maintenance (scheduled maintenance)
accepting_jobs Whether the backend is currently accepting new job submissions
queue_depth Number of jobs currently waiting in the queue
max_qubits Maximum number of qubits supported (from backend constraints)

Warning

Check that the backend is Online and accepting_jobs is true before submitting jobs. Submitting to an offline backend will result in a job failure.

  • Device Options -- Full list of device parameters including execution_plan and queue_priority.
  • Credits -- How backend choice affects pricing.
  • Backends -- Platform-level backend documentation.