simulator_stabilizer and simulator_extended_stabilizer simulator properties fail

[caleb-johnson]

Describe the bug
simulator_stabilizer and simulator_extended_stabilizer simulator properties crash the program ungracefully with a cryptic error message.

TranspilerError: "The number of qubits for Instruction(name='cx', num_qubits=2, num_clbits=0, params=[]) does not match the number of qubits in the properties dictionary: (0,)"

Steps to reproduce

from qiskit_ibm_runtime import QiskitRuntimeService

runtime_service = QiskitRuntimeService()
backend = runtime_service.get_backend("simulator_stabilizer")
# OR 
# backend = runtime_service.get_backend("simulator_extended_stabilizer")
backend.simulator # This line fails

Expected behavior
I believe these backends should report True, as they are simulators. If these methods can't/shouldn't be implemented, I would expect a NotImplementedError to be raised.

Suggested solutions

Additional Information

• qiskit-ibm-runtime version: 0.12.2
• Python version: 3.10
• Operating system: MacOS

[caleb-johnson]

Full trace of error:

  File "/repos_public_acct/qiskit-ibm-runtime/test.py", line 5, in <module>
    print(backend.simulator)
  File "/repos_public_acct/qiskit-ibm-runtime/qiskit_ibm_runtime/ibm_backend.py", line 212, in __getattr__
    self._convert_to_target()
  File "/repos_public_acct/qiskit-ibm-runtime/qiskit_ibm_runtime/ibm_backend.py", line 247, in _convert_to_target
    self._target = convert_to_target(
  File "/repos_public_acct/qiskit-ibm-runtime/qiskit_ibm_runtime/utils/backend_converter.py", line 118, in convert_to_target
    target.add_instruction(name_mapping[name], gate_props)
  File "/env/lib/python3.10/site-packages/qiskit/transpiler/target.py", line 424, in add_instruction
    raise TranspilerError(
qiskit.transpiler.exceptions.TranspilerError: "The number of qubits for Instruction(name='cx', num_qubits=2, num_clbits=0, params=[]) does not match the number of qubits in the properties dictionary: (0,)"

[1ucian0]

I can confirm that this issue is reproducible in 0.17.0:

from qiskit_ibm_runtime import QiskitRuntimeService
service = QiskitRuntimeService()
backend = service.get_backend('simulator_stabilizer')
backend.simulator

---------------------------------------------------------------------------
TranspilerError                           Traceback (most recent call last)
<ipython-input-21-25450b4bc7bc> in <module>
      2 service = QiskitRuntimeService()
      3 backend = service.get_backend('simulator_stabilizer')
----> 4 backend.simulator

qiskit_ibm_runtime/ibm_backend.py in __getattr__(self, name)
    226         self._get_properties()
    227         self._get_defaults()
--> 228         self._convert_to_target()
    229         # Check if the attribute now is available on IBMBackend class due to above steps
    230         try:

qiskit_ibm_runtime/ibm_backend.py in _convert_to_target(self, refresh)
    261         """Converts backend configuration, properties and defaults to Target object"""
    262         if refresh or not self._target:
--> 263             self._target = convert_to_target(
    264                 configuration=self._configuration,
    265                 properties=self._properties,

qiskit_ibm_runtime/utils/backend_converter.py in convert_to_target(configuration, properties, defaults)
    116             gate_len = len(gate.coupling_map[0]) if hasattr(gate, "coupling_map") else 0
    117             if name in name_mapping:
--> 118                 target.add_instruction(name_mapping[name], gate_props)
    119             else:
    120                 custom_gate = Gate(name, gate_len, [])

qiskit/transpiler/target.py in add_instruction(self, instruction, properties, name)
    428             for qarg in properties:
    429                 if qarg is not None and len(qarg) != instruction.num_qubits:
--> 430                     raise TranspilerError(
    431                         f"The number of qubits for {instruction} does not match the number "
    432                         f"of qubits in the properties dictionary: {qarg}"

TranspilerError: "The number of qubits for Instruction(name='cx', num_qubits=2, num_clbits=0, params=[]) does not match the number of qubits in the properties dictionary: (0,)"

[sr5434]

+1