StatevectorSampler reuses the same seed for all PUBs

[tnemoz]

Environment

• Qiskit version:
  1.3.0
• Python version:
  3.10.10
• Operating system:
  Ubuntu

What is happening?

When initialized with a seed, StatevectorSampler will reuse the same seed for all PUBs instead of generating a RNG once using this seed and then sticking to it. This causes undesired behaviors when running (close to) identical PUBs.

How can we reproduce the issue?

from qiskit import QuantumCircuit
from qiskit.primitives import StatevectorSampler

qc = QuantumCircuit(1)
qc.h(0)
qc.measure_all()

sampler = StatevectorSampler(seed=42)
res = sampler.run([(qc, None, 1) for _ in range(10)]).result()

for r in res:
    print(r.data.meas.get_int_counts())

What should happen?

The code should instantiate a RNG once using the provided seed and then generate subsequent random numbers using this generator for all PUBs without re-instantiate it with the provided seed, so that the experiment is reproducible, but results between PUBs are not correlated.

Any suggestions?

It's definitely a niche problem, that I noticed because I had to run identical QuantumCircuits among different PUBs, so I'd understand if this isn't fixed.