Feature/add qiskit api options

pytket/extensions/qiskit/backends/ibm.py

@@ -170,6 +170,13 @@ class IBMQBackend(Backend):
     :type provider: Optional[IBMProvider]
     :param token: Authentication token to use the `QiskitRuntimeService`.
     :type token: Optional[str]
+    :param options: A customised `qiskit_ibm_runtime` `Options` instance.
+        Passed to the qiskit sampler submission during
+        `process_circuit` (`process_circuits`). If the `Options` instance is not
+        specified, both `optimization_level` and `resilience_level` are set to 0,
+        and `skip_transpilation` is set to True. These default values can be customised
+        by using the `options` keyword argument.
+    :type options: Dict[str, int]
     """
 
     _supports_shots = False
@@ -184,6 +191,7 @@ def __init__(
         monitor: bool = True,
         provider: Optional["IBMProvider"] = None,
         token: Optional[str] = None,
+        options: Options = None,
     ):
         super().__init__()
         self._pytket_config = QiskitConfig.from_default_config_file()
@@ -214,6 +222,13 @@ def __init__(
         # cache of results keyed by job id and circuit index
         self._ibm_res_cache: Dict[Tuple[str, int], Counter] = dict()
 
+        if options is None:
+            options = Options()
+            options.optimization_level = 0
+            options.resilience_level = 0
+            options.transpilation.skip_transpilation = True
+        self._sampler_options = options
+
         self._MACHINE_DEBUG = False
 
     @staticmethod
@@ -503,7 +518,13 @@ def process_circuits(
                 apply the pytket ``SimplifyInitial`` pass to improve
                 fidelity of results assuming all qubits initialized to zero
                 (bool, default False)
-
+            * `options`:
+                Use a custom qiskit Options instance. This enables application of
+                error-mitigation and remote transpilation of circuits on
+                IBMQ Cloud. Values for `resilience_level` can be found
+                here: https://docs.quantum.ibm.com/run/configure-error-mitigation.
+                Values for `optimization_level` can be found here:
+                https://docs.quantum.ibm.com/run/configure-runtime-compilation
         """
         circuits = list(circuits)
 
@@ -519,6 +540,10 @@ def process_circuits(
         postprocess = kwargs.get("postprocess", False)
         simplify_initial = kwargs.get("simplify_initial", False)
 
+        options: Options = kwargs.get("options")
+        if options is None:
+            options = self._sampler_options
+
         batch_id = 0  # identify batches for debug purposes only
         for (n_shots, batch), indices in zip(circuit_batches, batch_order):
             for chunk in itertools.zip_longest(
@@ -552,10 +577,6 @@ def process_circuits(
                             ppcirc_strs[i],
                         )
                 else:
-                    options = Options()
-                    options.optimization_level = 0
-                    options.resilience_level = 0
-                    options.transpilation.skip_transpilation = True
                     options.execution.shots = n_shots
                     sampler = Sampler(session=self._session, options=options)
                     job = sampler.run(