Fix for qiskit ibm runtime v 0.22 (#376)

ValentinS4t1qbit · Valentin Senicourt · web-flow · commit c4514bfe3aab · 2024-04-12T14:26:56.000-07:00
Co-authored-by: Valentin Senicourt &lt;valentin.senicourt@1qbit.com&gt;
diff --git a/tangelo/linq/qpu_connection/ibm_connection.py b/tangelo/linq/qpu_connection/ibm_connection.py
@@ -9,6 +9,7 @@
 from tangelo.linq.qpu_connection.qpu_connection import QpuConnection
 
 try:
+    from qiskit import QuantumCircuit, QuantumRegister
     from qiskit.providers.jobstatus import JobStatus
     from qiskit.primitives import SamplerResult, EstimatorResult
     from qiskit_ibm_runtime import QiskitRuntimeService, Sampler, Estimator, Session, Options
@@ -76,9 +77,13 @@ def job_submit(self, program, backend_name, n_shots, circuits, operators=None, r
             circuits = [circuits]
         qiskit_cs = list()
         for c in circuits:
-            qiskit_c = translate_circuit(c, target="qiskit")
-            qiskit_c.remove_final_measurements()
-            qiskit_c.measure_all(add_bits=False)
+
+            if program == 'sampler':
+                qiskit_c = translate_circuit(c, target="qiskit")
+                qiskit_c.remove_final_measurements()
+                qiskit_c.measure_all(add_bits=False)
+            elif program == 'estimator':
+                qiskit_c = translate_circuit(c, target="qiskit", output_options={'no_classical_register': True})
             qiskit_cs.append(qiskit_c)
 
         # If needed, translate qubit operators in qiskit format
@@ -130,7 +135,7 @@ def job_results(self, job_id):
             return None
 
         result = job.result()
-        self.jobs_results[job_id] = job._results
+        self.jobs_results[job_id] = job.result()
 
         # Sampler: return histogram for user in standard Tangelo format
         if isinstance(result, SamplerResult):
diff --git a/tangelo/linq/tests/test_ibm_connection.py b/tangelo/linq/tests/test_ibm_connection.py
@@ -26,7 +26,7 @@
 sim = get_backend()
 ref_estimator = sim.get_expectation_value(op, circ2)
 
-os.environ['IBM_TOKEN'] = 'INSERT YOUR TOKEN HERE'
+os.environ['IBM_TOKEN'] = 'INSERT TOKEN HERE'
 
 
 @unittest.skip("We do not want to store login information for automated testing. Manual testing only.")
diff --git a/tangelo/linq/translator/translate_qiskit.py b/tangelo/linq/translator/translate_qiskit.py
@@ -65,13 +65,14 @@ def get_qiskit_gates():
     return GATE_QISKIT
 
 
-def translate_c_to_qiskit(source_circuit: Circuit, save_measurements=False):
+def translate_c_to_qiskit(source_circuit: Circuit, save_measurements=False, no_classical_register=False):
     """Take in a Circuit, return an equivalent qiskit.QuantumCircuit
 
     Args:
         source_circuit (Circuit): quantum circuit in the abstract format.
         save_measurements (bool): Return mid-circuit measurements in the order
             they appear in the circuit in the classical registers
+        no_classical_register (bool): do not create classical register in circuit (default: False)
 
     Returns:
         qiskit.QuantumCircuit: the corresponding qiskit.QuantumCircuit
@@ -82,7 +83,12 @@ def translate_c_to_qiskit(source_circuit: Circuit, save_measurements=False):
 
     n_meas = source_circuit._gate_counts.get("MEASURE", 0) if save_measurements else 0
     n_measures = n_meas + source_circuit.width
-    target_circuit = qiskit.QuantumCircuit(source_circuit.width, n_measures)
+    if no_classical_register:
+        if n_meas != 0:
+            print('Linq translator warning :: Qiskit circuit instantiated with no classical register but measurement gates are present')
+        target_circuit = qiskit.QuantumCircuit(source_circuit.width)
+    else:
+        target_circuit = qiskit.QuantumCircuit(source_circuit.width, n_measures)
 
     measurement = 0
 
