Qiskit Runtime Sampler , sampler not taking the argument "backend"

[sirgeorgesawcon]

Environment

• Qiskit Terra version: 0.22.2
• Python version: 3.8.1
• Operating system: Win10

What is happening?

Following the Qiskit tutorial on sampler : https://qiskit.org/ecosystem/ibm-runtime/tutorials/how-to-getting-started-with-sampler.html

while invoking the Qiskit runtime sampler, with any backend (backend = ibmq_qasm_simulator) and then running the

sampler = Sampler(backend=backend)

gives the error: TypeError: Sampler.init() got an unexpected keyword argument 'backend'

It should not happen, since the sampler function in qiskit takes in the following input

but here it's flagging backend as unexpected keyword

How can we reproduce the issue?

service = QiskitRuntimeService(channel="ibm_quantum")
backend = service.backend("ibmq_qasm_simulator")

from qiskit_ibm_runtime import Sampler

sampler = Sampler(backend=backend)

What should happen?

Sampler should take in the backend and then when executed with a quantum circuit qc should return the job results.

Any suggestions?

No response

[1ucian0]

It seems to be a problem related with an out-of-sync version of qiskit-ibm-runtime. What's your qiskit-ibm-runtime version?

from qiskit_ibm_runtime import __version__
print(__version__)

If lower than 0.11, consider updating your package pip install -U qiskit-ibm-runtime

[sirgeorgesawcon]

It's again giving the same issue:

[jyu00]

@sirgeorgesawcon Where did you import that Sampler from? The tutorial first shows how to use Sampler from Qiskit (terra) by first doing from qiskit.primitives import Sampler. Then later it shows using Qiskit Runtime Sampler by first doing from qiskit_ibm_runtime import Sampler.

qiskit.primitives.Sampler doesn't accept backend as an input argument.

[sirgeorgesawcon]

This is how I'm importing Sampler

[kt474]

@sirgeorgesawcon if you're using the latest version of qiskit-ibm-runtime, the following code snippet should work - as mentioned in the comment above, I believe you're not actually using the Sampler imported from qiskit_ibm_runtime but using the Sampler imported from qiskit.primitives.

from qiskit_ibm_runtime import QiskitRuntimeService, Sampler

service = QiskitRuntimeService(channel="ibm_quantum")
backend = service.backend("ibmq_qasm_simulator")

sampler = Sampler(backend=backend)

[sirgeorgesawcon]

Hi, Yes, It is running perfectly now, thanks, The issue was that in the big file of imports, I was importing sampler twice, first from runtime and second from aer. Now it's working fine. But the sampler from aer gives a different result than sampler from runtime.

I understand that sampler from aer is running on my local machine, and sampler from runtime is running on IBM cloud and specifically ibm_qasm_simulator, given the Qasm Simulator is noise free simulator, both the results should be the same, But the aer sampler gives the result that matches with the classical and runtime sampler gives different result than that.

[kt474]

Closing for now, following up discussion in #1043