How to Run a Dynamic Qiskit Circuit Using the Sampler Primitive?

Question

I aim to execute my Qiskit dynamic circuit using a sampler. The rationale behind this choice is that a sampler allows me to run multiple circuits concurrently, whereas using a backend restricts me to executing one circuit at a time. However, while I have developed the code, I am uncertain about where to specify the 'dynamic=True' parameter.

Code:

from qiskit_ibm_runtime import QiskitRuntimeService, Sampler
from qiskit import QuantumCircuit

service = QiskitRuntimeService(
    channel='ibm_quantum',
    instance='ibm-q/open/main',
)

bell = QuantumCircuit(2,1)
bell.h(0)
bell.x(res[0]).c_if(cr, 0) # 
bell.cx(0, 1)
bell.x(res[1]).c_if(cr, 0) # 
bell.measure_all()

# executes three Bell circuits
with Sampler(
    circuits=[bell] * 3,
    service=service,
    options={'backend': 'ibmq_qasm_simulator'},
) as sampler:
    # alternatively you can also pass circuits as objects
    result = sampler(circuits=[bell] * 3)
    print(result)

Answer 1

At the moment, Qiskit Runtime does not enable you to run dynamic circuits (so you cannot use Sampler primitive on a Runtime backend) as shown here: https://qiskit.org/ecosystem/ibm-runtime/compare.html.

However, in the last update of Qiskit IBM provider; we can now wrap the backend.run call within a Session as well, enabling you to do what you want: https://qiskit.org/ecosystem/ibm-provider/stubs/qiskit_ibm_provider.Session.html And use BackendSampler.run() with the circuits that you want (which this time can be set as Dynamic circuits as you’re using the usual IBM provider. You should therefore put the dynamic=True parameter in the IBm provider backend options once it is declared.