Merge remote-tracking branch 'upstream/master' into readout_sampling

CHANGELOG.md

@@ -25,6 +25,8 @@ Added
 -   Added support for conditional unitary, kraus, superop qobj instructions (\# 291)
 -   Add "validation_threshold" config parameter to Aer backends (\# 290)
 
+- Noise model inserter module
+
 Changed
 -------
 
@@ -37,6 +39,8 @@ Fixed
 -----
 - Bug in handling parallelization in matrix_product_state.cpp (PR \#292)
 
+- Added support for multiplication by coeff in tensor_network_state expectation value snapshots (PR \#294)
+
 
 [0.2.3](https://github.com/Qiskit/qiskit-aer/compare/0.2.2...0.2.3) - 2019-07-11
 ===============================================================================

contrib/standalone/qasm_simulator.cpp

@@ -133,15 +133,14 @@ int main(int argc, char **argv) {
   // Execute simulation
   try {
 
-    // Initialize simulator
-    AER::Simulator::QasmController sim;
-
-    // Check for config
-    json_t config_all = qobj["config"];
+    // Check for command line config
+    // and if present add to qobj config
+    json_t& config_all = qobj["config"];
     if (!config.empty())
       config_all.update(config.begin(), config.end());
 
-    sim.set_config(config_all);
+    // Initialize simulator
+    AER::Simulator::QasmController sim;
     auto result = sim.execute(qobj);
     out << result.dump(4) << std::endl;
 

qiskit/providers/aer/backends/qasm_simulator.py

@@ -20,7 +20,6 @@
 from .aerbackend import AerBackend
 # pylint: disable=import-error
 from .qasm_controller_wrapper import qasm_controller_execute
-from ..aererror import AerError
 from ..version import __version__
 
 logger = logging.getLogger(__name__)
@@ -230,29 +229,3 @@ def _validate(self, qobj, backend_options, noise_model):
                 logger.warning(
                     'No measurements in circuit "%s": '
                     'count data will return all zeros.', name)
-            # Check qubits for statevector simulation
-            if not clifford and method != "extended_stabilizer":
-                n_qubits = experiment.config.n_qubits
-                max_qubits = self.configuration().n_qubits
-                if n_qubits > max_qubits:
-                    system_memory = int(local_hardware_info()['memory'])
-                    err_string = ('Number of qubits ({}) is greater than '
-                                  'maximum ({}) for "{}" (method=statevector) '
-                                  'with {} GB system memory')
-                    err_string = err_string.format(n_qubits, max_qubits,
-                                                   self.name(), system_memory)
-                    if method != "automatic":
-                        raise AerError(err_string + '.')
-
-                    if n_qubits > 63:
-                        raise AerError('{}, and has too many qubits to fall '
-                                       'back to the extended_stabilizer '
-                                       'method.'.format(err_string))
-                    if not ch_supported:
-                        raise AerError('{}, and contains instructions '
-                                       'not supported by the extended_etabilizer '
-                                       'method.'.format(err_string))
-                    logger.info(
-                        'The QasmSimulator will automatically '
-                        'switch to the Extended Stabilizer backend, based on '
-                        'the memory requirements.')

qiskit/providers/aer/backends/wrappers/qasm_controller_wrapper.pyx

@@ -20,7 +20,7 @@ cdef extern from "simulators/qasm/qasm_controller.hpp" namespace "AER::Simulator
     cdef cppclass QasmController:
         QasmController() except +
 
-cdef extern from "base/controller.hpp" namespace "AER":
+cdef extern from "simulators/controller_execute.hpp" namespace "AER":
     cdef string controller_execute[QasmController](string &qobj) except +
 
 

qiskit/providers/aer/backends/wrappers/statevector_controller_wrapper.pyx

@@ -20,7 +20,7 @@ cdef extern from "simulators/statevector/statevector_controller.hpp" namespace "
     cdef cppclass StatevectorController:
         StatevectorController() except +
 
-cdef extern from "base/controller.hpp" namespace "AER":
+cdef extern from "simulators/controller_execute.hpp" namespace "AER":
     cdef string controller_execute[StatevectorController](string &qobj) except +
 
 

qiskit/providers/aer/backends/wrappers/unitary_controller_wrapper.pyx

@@ -20,7 +20,7 @@ cdef extern from "simulators/unitary/unitary_controller.hpp" namespace "AER::Sim
     cdef cppclass UnitaryController:
         UnitaryController() except +
 
-cdef extern from "base/controller.hpp" namespace "AER":
+cdef extern from "simulators/controller_execute.hpp" namespace "AER":
     cdef string controller_execute[UnitaryController](string &qobj) except +
 
 

qiskit/providers/aer/noise/utils/__init__.py

@@ -18,3 +18,4 @@
 from .noise_transformation import NoiseTransformer
 from .noise_transformation import approximate_quantum_error
 from .noise_transformation import approximate_noise_model
+from .noise_model_inserter import insert_noise

qiskit/providers/aer/noise/utils/noise_model_inserter.py

@@ -0,0 +1,51 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2019.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+"""
+Noise model inserter module
+The goal of this module is to add QuantumError gates (Kraus gates) to a circuit
+based on a given noise model. The resulting circuit cannot be ran on a quantum computer
+but can be handled correctly by simulators
+"""
+import qiskit.compiler
+
+
+def insert_noise(circuits, noise_model, transpile=False):
+    """
+        This function gets a circuit and a noise model and returns a new circuit
+        with the noises from the noise model inserted as Kraus gates in the new circuit
+        Args:
+            circuits (QuantumCircuit or list[QuantumCircuit]): The circuits to add noises to
+            noise_model (NoiseModel):  The noise model containing the errors to add
+            transpile (Boolean): Should the circuit be transpiled into the noise model basis gates
+        Returns:
+            QuantumCircuit: The new circuit with the added Kraus gates
+        """
+    is_circuits_list = isinstance(circuits, (list, tuple))
+    circuits = circuits if is_circuits_list else [circuits]
+    result_circuits = []
+    errors = noise_model._default_quantum_errors.items()
+    error_dict = {name: qubit_dict for (name, qubit_dict) in errors}
+    for circuit in circuits:
+        if transpile:
+            transpiled_circuit = qiskit.compiler.transpile(circuit,
+                                                           basis_gates=noise_model.basis_gates)
+        else:
+            transpiled_circuit = circuit
+        result_circuit = circuit.copy(name=transpiled_circuit.name + '_with_noise')
+        result_circuit.data = []
+        for inst, qargs, cargs in transpiled_circuit.data:
+            result_circuit.data.append((inst, qargs, cargs))
+            if inst.name in error_dict.keys():
+                error = error_dict[inst.name]
+                result_circuit.append(error.to_instruction(), qargs)
+        result_circuits.append(result_circuit)
+    return result_circuits if is_circuits_list else result_circuits[0]