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Backends

Open Quantum provides access to quantum processing units (QPUs) through a unified interface. Each backend is represented as a backend class with a unique short code.

Backend Types

Type Description
QPU Real quantum hardware. Circuits run on physical qubits with real noise characteristics.

Backend Properties

Each backend exposes the following properties:

Property Type Description
id UUID Unique identifier.
short_code string Human-readable identifier (e.g., ionq:forte-1). Used as the backend parameter in all SDKs.
name string Display name.
type QPU Backend type.
status Online, Offline, or Maintenance Current operational state of the backend.
accepting_jobs boolean Whether the backend is accepting new job submissions.
queue_depth integer Number of jobs currently waiting in the queue.

Backend Status

Status Meaning
Online The backend is operational and can execute jobs.
Offline The backend is unavailable (hardware issues or other problems).
Maintenance The backend is temporarily unavailable for scheduled maintenance.

Note

A backend can be Online but have accepting_jobs: false if it is temporarily paused for job intake (e.g., during calibration). Check both fields before submitting jobs.

Listing Backends

from openquantum_sdk.clients import ManagementClient

management = ManagementClient(auth=auth)
result = management.list_backend_classes()
for bc in result.backend_classes:
    print(f"{bc.short_code}: {bc.name} ({bc.type})")

from openquantum_sdk_qiskit import OpenQuantumService

service = OpenQuantumService()
backends = service.backends(online=True)
for b in backends:
    print(f"{b['short_code']}: {b['name']} ({b['type']})")

PennyLane devices are created by short code. Use the Core SDK's ManagementClient to discover available backends, then pass the short code to qml.device:

from openquantum_sdk.clients import ManagementClient
import pennylane as qml

# List available backends
management = ManagementClient(auth=auth)
result = management.list_backend_classes()
for bc in result.backend_classes:
    print(f"{bc.short_code}: {bc.name} ({bc.type})")

# Create a device targeting any available backend
dev = qml.device("openquantum.device", wires=2, shots=1024,
                  backend="ionq:forte-1")