Transpiling to IonQ from Qiskit

Question

Hello, I just have a quick question regarding the Qiskit initialization method. It takes a pretty long time ~1min to transpile my 10q circuit to IonQ backends, as opposed to the ~1s for ibmq backends. Does anyone know of better native IonQ implementation to initialize in Qiskit?

Answer 1

I am not expert in AS but I checked many blogs and I understood that Transpiling quantum circuits for IonQ backends in Qiskit can indeed take longer compared to IBMQ backends. This difference arises from the distinct native gate sets and architectures of the two platforms, which necessitate different transpilation processes.

Transpilation involves converting a high-level quantum circuit into a form that aligns with the specific hardware constraints and native gate sets of a quantum backend. IonQ's trapped-ion systems support a broad set of gates, including native gates like rx, ry, rz, xx, and zz . In contrast, IBMQ's superconducting qubits have a different set of native gates. This discrepancy means that circuits often require more extensive transformations to fit IonQ's architecture, leading to longer transpilation times.

By explicitly defining IonQ's native gates during transpilation, you can reduce unnecessary gate decompositions. This approach helps the transpiler generate circuits that are more compatible with IonQ's hardware, potentially reducing transpilation time.

from qiskit import transpile

# Define your quantum circuit as 'qc'

ionq_basis_gates = ['rx', 'ry', 'rz', 'xx', 'zz']

transpiled_circuit = transpile(qc, basis_gates=ionq_basis_gates)

Qiskit's transpiler offers different optimization levels (0 to 3), with higher levels providing more optimization at the cost of increased transpilation time . Experimenting with lower optimization levels may yield faster transpilation without significantly affecting circuit performance.

transpiled_circuit = transpile(qc, optimization_level=1)

IonQ's provider for Qiskit includes its own transpilation and compilation pipeline, which is tailored to their hardware . Leveraging this pipeline can streamline the transpilation process.

from qiskit_ionq import IonQProvider

provider = IonQProvider('your_ionq_api_key')

backend = provider.get_backend('ionq_qpu')

job = backend.run(qc)

result = job.result()

Additional Considerations:

• The structure and complexity of your quantum circuit significantly influence transpilation time. Simplifying the circuit or breaking it into smaller sub-circuits can help reduce transpilation duration.
• Be mindful of the specific constraints and capabilities of IonQ's hardware, such as qubit connectivity and gate durations, as these factors affect the transpilation process.