The following error occurs when executing the code to measure the dephasing time(T2). I would appreciate it if someone could give me a solution to this problem. Among the two functions below, widthoutDelay() performs normally, and the function withDelay() fails with the attached error.
Additionally, where can I find an example code to measure the time-dependent dephasing of the qubit? Some of the sample codes are from a few years ago, so there are a lot of contents that have been depreciated.
--------------------------- Execution Code in jupyter ---------------------------
from qiskit import QuantumRegister, ClassicalRegister
from qiskit import QuantumCircuit, execute,IBMQ
from qiskit.tools.monitor import job_monitor
from qiskit import transpile
import numpy
pi = numpy.pi
IBMQ.load_account()
provider = IBMQ.get_provider(hub='ibm-q')
backend = provider.get_backend('ibm_nairobi')
q = QuantumRegister(1,'q')
c = ClassicalRegister(1,'c')
def withoutDelay():
circuit = QuantumCircuit(q,c)
circuit.h(q[0])
circuit.h(q[0])
circuit.measure(q[0],c[0]) #Measuring the qubit
nShots = 8192
job = execute(circuit, backend, shots=nShots)
job_monitor(job)
counts = job.result().get_counts()
print("No delay: ",counts)
def withDelay():
circuit = QuantumCircuit(q,c)
circuit.h(q[0])
circuit.delay(283, unit="us") # Delay of 200.79 microseconds
circuit.h(q[0])
circuit.measure(q[0],c[0]) #Measuring the qubit
transpiled_circ = transpile(circuit, backend, scheduling_method='alap')
nShots = 8192
job = execute(transpiled_circ, backend, shots=nShots)
job_monitor(job)
counts = job.result().get_counts()
print("With delay: ",counts)
withoutDelay()
withDelay()
--------------------------- Error Message ---------------------------
Job Status: job has successfully run
No delay: {'0': 8111, '1': 81}
---------------------------------------------------------------------------
TranspilerError Traceback (most recent call last)
Input In [19], in ()
49 print("With delay: ",counts)
51 withoutDelay()
---> 52 withDelay()
Input In [19], in withDelay()
40 transpiled_circ = transpile(circuit, backend, scheduling_method='alap')
42 nShots = 8192
---> 44 job = execute(transpiled_circ, backend, shots=nShots)
45 job_monitor(job)
47 counts = job.result().get_counts()
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/execute_function.py:299, in execute(experiments, backend, basis_gates, coupling_map, backend_properties, initial_layout, seed_transpiler, optimization_level, pass_manager, qobj_id, qobj_header, shots, memory, max_credits, seed_simulator, default_qubit_los, default_meas_los, qubit_lo_range, meas_lo_range, schedule_los, meas_level, meas_return, memory_slots, memory_slot_size, rep_time, rep_delay, parameter_binds, schedule_circuit, inst_map, meas_map, scheduling_method, init_qubits, **run_config)
296 experiments = pass_manager.run(experiments)
297 else:
298 # transpiling the circuits using given transpile options
--> 299 experiments = transpile(
300 experiments,
301 basis_gates=basis_gates,
302 coupling_map=coupling_map,
303 backend_properties=backend_properties,
304 initial_layout=initial_layout,
305 seed_transpiler=seed_transpiler,
306 optimization_level=optimization_level,
307 backend=backend,
308 )
310 if schedule_circuit:
311 experiments = schedule(
312 circuits=experiments,
313 backend=backend,
(...)
316 method=scheduling_method,
317 )
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/compiler/transpiler.py:341, in transpile(circuits, backend, basis_gates, inst_map, coupling_map, backend_properties, initial_layout, layout_method, routing_method, translation_method, scheduling_method, instruction_durations, dt, approximation_degree, timing_constraints, seed_transpiler, optimization_level, callback, output_name, unitary_synthesis_method, unitary_synthesis_plugin_config, target)
338 for circuit, unique_args in zip(circuits, unique_transpile_args):
339 transpile_config, pass_manager = _combine_args(shared_args, unique_args)
340 output_circuits.append(
--> 341 _serial_transpile_circuit(
342 circuit,
343 pass_manager,
344 transpile_config["callback"],
345 transpile_config["output_name"],
346 transpile_config["backend_num_qubits"],
347 transpile_config["faulty_qubits_map"],
348 transpile_config["pass_manager_config"].backend_properties,
349 )
350 )
351 circuits = output_circuits
352 end_time = time()
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/compiler/transpiler.py:434, in _serial_transpile_circuit(circuit, pass_manager, callback, output_name, num_qubits, faulty_qubits_map, backend_prop)
425 def _serial_transpile_circuit(
426 circuit,
427 pass_manager,
(...)
432 backend_prop=None,
433 ):
--> 434 result = pass_manager.run(circuit, callback=callback, output_name=output_name)
435 if faulty_qubits_map:
436 return _remap_circuit_faulty_backend(
437 result,
438 num_qubits,
439 backend_prop,
440 faulty_qubits_map,
441 )
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/passmanager.py:507, in StagedPassManager.run(self, circuits, output_name, callback)
500 def run(
501 self,
502 circuits: Union[QuantumCircuit, List[QuantumCircuit]],
503 output_name: str = None,
504 callback: Callable = None,
505 ) -> Union[QuantumCircuit, List[QuantumCircuit]]:
506 self._update_passmanager()
--> 507 return super().run(circuits, output_name, callback)
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/passmanager.py:224, in PassManager.run(self, circuits, output_name, callback)
222 return circuits
223 if isinstance(circuits, QuantumCircuit):
--> 224 return self._run_single_circuit(circuits, output_name, callback)
225 if len(circuits) == 1:
226 return self._run_single_circuit(circuits[0], output_name, callback)
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/passmanager.py:279, in PassManager._run_single_circuit(self, circuit, output_name, callback)
267 """Run all the passes on a ``circuit``.
268
269 Args:
(...)
276 The transformed circuit.
277 """
278 running_passmanager = self._create_running_passmanager()
--> 279 result = running_passmanager.run(circuit, output_name=output_name, callback=callback)
280 self.property_set = running_passmanager.property_set
281 return result
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/runningpassmanager.py:124, in RunningPassManager.run(***failed resolving arguments***)
122 for passset in self.working_list:
123 for pass_ in passset:
--> 124 dag = self._do_pass(pass_, dag, passset.options)
126 circuit = dag_to_circuit(dag)
127 if output_name:
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/runningpassmanager.py:167, in RunningPassManager._do_pass(self, pass_, dag, options)
165 # Run the pass itself, if not already run
166 if pass_ not in self.valid_passes:
--> 167 dag = self._run_this_pass(pass_, dag)
169 # update the valid_passes property
170 self._update_valid_passes(pass_)
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/runningpassmanager.py:221, in RunningPassManager._run_this_pass(self, pass_, dag)
218 elif pass_.is_analysis_pass:
219 # Measure time if we have a callback or logging set
220 start_time = time()
--> 221 pass_.run(FencedDAGCircuit(dag))
222 end_time = time()
223 run_time = end_time - start_time
File ~/anaconda3/envs/qiskit/lib/python3.10/site-packages/qiskit/transpiler/passes/scheduling/alignments/reschedule.py:206, in ConstrainedReschedule.run(self, dag)
170 """Run rescheduler.
171
172 This pass should perform rescheduling to satisfy:
(...)
202 TranspilerError: If circuit is not scheduled.
203 """
205 if "node_start_time" not in self.property_set:
--> 206 raise TranspilerError(
207 f"The input circuit {dag.name} is not scheduled. Call one of scheduling passes "
208 f"before running the {self.__class__.__name__} pass."
209 )
211 node_start_time = self.property_set["node_start_time"]
213 for node in dag.topological_op_nodes():
TranspilerError: 'The input circuit None is not scheduled. Call one of scheduling passes before running the ConstrainedReschedule pass.'
