bug in Estimator for parameterized dynamic circuits

[ajavadia]

Informations

• Qiskit Aer version: 0.12.1
• Python version: 3.8
• Operating system: mac

What is the current behavior?

The following circuit has two angle parameters s and t, and it fails in the estimator with:
ERROR: Failed to load circuits: Invalid parameterization: instruction param position out of range

from qiskit.circuit import QuantumCircuit, ClassicalRegister, Parameter
from qiskit.quantum_info import SparsePauliOp
from qiskit_aer.primitives import Estimator

estimator = Estimator(run_options={'shots': 1000})
t = Parameter('t')
s = Parameter('s')

# dynamic circuit
circ2 = QuantumCircuit(4)
circ2.add_register(ClassicalRegister(2, 'cr'))
circ2.cx(0, 2)
circ2.cx(1, 2)
circ2.rz(t, 2)
circ2.h(2)
circ2.measure(2, 0)
circ2.z(0).c_if(0, 1)
circ2.z(1).c_if(0, 1)
circ2.barrier()
#circ2.x(2).c_if(0, 1)
circ2.h(0)
circ2.cx(0, 3)
circ2.cx(1, 3)
circ2.rz(s, 3)
circ2.h(3)
circ2.measure(3, 0)
circ2.z(0).c_if(0, 1)
circ2.z(1).c_if(0, 1)
circ2.barrier()
print(circ2.draw(fold=60))

obs2 = SparsePauliOp('IIZY')
values2 = [[1.57, 1.56]]
res2 = estimator.run(circ2, obs2, values2).result()
print(res2)

But it works when the parameters are removed and replaced with concrete angles.

This may be related to how the instructions and parameters of the circuit are parsed with Aer. In terra this should be trivial to bind a circuit with a list of parameters so I'm not sure why it fails in Aer / if it's trying to do something custom?