AerSimulator from V1 backend errors with delay circuits

[chriseclectic]

Informations

• Qiskit Aer version: 0.14.1
• Python version: 3.11
• Operating system: MacOS

What is the current behavior?

Running a scheduled circuit containing delay gates errors on Qiskit Aer 0.14 if the AerSimulator is initialized from a V1 backend.

Steps to reproduce the problem

from qiskit_ibm_runtime.fake_provider import FakeVigo
from qiskit_aer import AerSimulator
from qiskit import QuantumCircuit, transpile

backend = AerSimulator.from_backend(FakeVigo())
qc = QuantumCircuit(5)
qc.cx(0, 1)
qc.cx(1, 2)
qc.measure_all()
tqc = transpile(qc, backend, scheduling_method="alap")

backend.run([tqc]).result()

Errors with

---------------------------------------------------------------------------
AerError                                  Traceback (most recent call last)
Cell In[1], line 12
      9 qc.measure_all()
     10 tqc = transpile(qc, backend, scheduling_method="alap")
---> 12 backend.run([tqc]).result()

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/jobs/utils.py:42, in requires_submit.<locals>._wrapper(self, *args, **kwargs)
     40 if self._future is None:
     41     raise JobError("Job not submitted yet!. You have to .submit() first!")
---> 42 return func(self, *args, **kwargs)

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/jobs/aerjob.py:114, in AerJob.result(self, timeout)
     96 @requires_submit
     97 def result(self, timeout=None):
     98     # pylint: disable=arguments-differ
     99     """Get job result. The behavior is the same as the underlying
    100     concurrent Future objects,
    101 
   (...)
    112         concurrent.futures.CancelledError: if job cancelled before completed.
    113     """
--> 114     return self._future.result(timeout=timeout)

File ~/mambaforge/envs/qiskit1/lib/python3.11/concurrent/futures/_base.py:456, in Future.result(self, timeout)
    454     raise CancelledError()
    455 elif self._state == FINISHED:
--> 456     return self.__get_result()
    457 else:
    458     raise TimeoutError()

File ~/mambaforge/envs/qiskit1/lib/python3.11/concurrent/futures/_base.py:401, in Future.__get_result(self)
    399 if self._exception:
    400     try:
--> 401         raise self._exception
    402     finally:
    403         # Break a reference cycle with the exception in self._exception
    404         self = None

File ~/mambaforge/envs/qiskit1/lib/python3.11/concurrent/futures/thread.py:58, in _WorkItem.run(self)
     55     return
     57 try:
---> 58     result = self.fn(*self.args, **self.kwargs)
     59 except BaseException as exc:
     60     self.future.set_exception(exc)

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/backends/aerbackend.py:454, in AerBackend._execute_circuits_job(self, circuits, parameter_binds, run_options, job_id, format_result)
    451 circuits, noise_model = self._compile(circuits, **run_options)
    453 if self._target is not None:
--> 454     aer_circuits, idx_maps = assemble_circuits(circuits, self.configuration().basis_gates)
    455 else:
    456     aer_circuits, idx_maps = assemble_circuits(circuits)

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/backends/aer_compiler.py:959, in assemble_circuits(circuits, basis_gates)
    956 if basis_gates is not None:
    957     basis_gates_set = set(basis_gates)
    958     aer_circuits, idx_maps = zip(
--> 959         *[assemble_circuit(circuit, basis_gates_set) for circuit in circuits]
    960     )
    961 else:
    962     aer_circuits, idx_maps = zip(*[assemble_circuit(circuit) for circuit in circuits])

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/backends/aer_compiler.py:959, in <listcomp>(.0)
    956 if basis_gates is not None:
    957     basis_gates_set = set(basis_gates)
    958     aer_circuits, idx_maps = zip(
--> 959         *[assemble_circuit(circuit, basis_gates_set) for circuit in circuits]
    960     )
    961 else:
    962     aer_circuits, idx_maps = zip(*[assemble_circuit(circuit) for circuit in circuits])

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/backends/aer_compiler.py:681, in assemble_circuit(circuit, basis_gates)
    678     elif hasattr(inst.operation, "condition_expr") and inst.operation.condition_expr:
    679         conditional_expr = inst.operation.condition_expr
--> 681     num_of_aer_ops += _assemble_op(
    682         circuit,
    683         aer_circ,
    684         inst,
    685         qubit_indices,
    686         clbit_indices,
    687         is_conditional,
    688         conditional_reg,
    689         conditional_expr,
    690         basis_gates,
    691     )
    692     index_map.append(num_of_aer_ops - 1)
    694 return aer_circ, index_map

File ~/mambaforge/envs/qiskit1/lib/python3.11/site-packages/qiskit_aer/backends/aer_compiler.py:926, in _assemble_op(circ, aer_circ, inst, qubit_indices, clbit_indices, is_conditional, conditional_reg, conditional_expr, basis_gates)
    921     raise AerError(
    922         "control-flow instructions must be converted " f"to jump and mark instructions: {name}"
    923     )
    925 else:
--> 926     raise AerError(f"unknown instruction: {name}")
    928 return num_of_aer_ops

AerError: 'unknown instruction: delay'

What is the expected behavior?

The above code worked correctly with Aer 0.13.3, it also works correctly for V2 fake backends in Aer 0.14

Suggested solutions

There looks like there is a bug in _assemble_op where it expects "delay" to be in a backends basis gates, but ibm backends don't report delay as a basis gate.