Release 0.7.0 (#993)

* Move release notes to 0.7 folder

* Update readme example to include ideal and noisy simulation

README.md

@@ -41,43 +41,41 @@ $ python
 ```
 
 ```python
-from qiskit import QuantumCircuit, execute
-from qiskit import Aer, IBMQ
-from qiskit.providers.aer.noise import NoiseModel
-
-# Choose a real device to simulate from IBMQ provider
-provider = IBMQ.load_account()
-backend = provider.get_backend('ibmq_vigo')
-coupling_map = backend.configuration().coupling_map
-
-# Generate an Aer noise model for device
-noise_model = NoiseModel.from_backend(backend)
-basis_gates = noise_model.basis_gates
+import qiskit
+from qiskit import IBMQ
+from qiskit.providers.aer import QasmSimulator
 
 # Generate 3-qubit GHZ state
-num_qubits = 3
-circ = QuantumCircuit(3, 3)
+circ = qiskit.QuantumCircuit(3, 3)
 circ.h(0)
 circ.cx(0, 1)
 circ.cx(1, 2)
 circ.measure([0, 1, 2], [0, 1 ,2])
 
+# Construct an ideal simulator
+sim = QasmSimulator()
+
+# Perform an ideal simulation
+result_ideal = qiskit.execute(circ, sim).result()
+counts_ideal = result_ideal.get_counts(0)
+print('Counts(ideal):', counts_ideal)
+# Counts(ideal): {'000': 493, '111': 531}
+
+# Construct a noisy simulator backend from an IBMQ backend
+# This simulator backend will be automatically configured
+# using the device configuration and noise model 
+provider = IBMQ.load_account()
+vigo_backend = provider.get_backend('ibmq_vigo')
+vigo_sim = QasmSimulator.from_backend(vigo_backend)
+
 # Perform noisy simulation
-backend = Aer.get_backend('qasm_simulator')
-job = execute(circ, backend,
-              coupling_map=coupling_map,
-              noise_model=noise_model,
-              basis_gates=basis_gates)
-result = job.result()
-
-print(result.get_counts(0))
-```
+result_noise = qiskit.execute(circ, vigo_sim).result()
+counts_noise = result_noise.get_counts(0)
 
-```python
-{'000': 495, '001': 18, '010': 8, '011': 18, '100': 2, '101': 14, '110': 28, '111': 441}
+print('Counts(noise):', counts_noise)
+# Counts(noise): {'000': 492, '001': 6, '010': 8, '011': 14, '100': 3, '101': 14, '110': 18, '111': 469}
 ```
 
-
 ## Contribution Guidelines
 
 If you'd like to contribute to Qiskit, please take a look at our

qiskit/providers/aer/noise/errors/readout_error.py

@@ -42,7 +42,7 @@ def __init__(self, probabilities, atol=ATOL_DEFAULT):
 
         .. code-block:: python
 
-            probabilities[j] = [P(0|m), P(1|m), ..., P(2 ** N - 1|m)]
+            probabilities[m] = [P(0|m), P(1|m), ..., P(2 ** N - 1|m)]
 
         where ``P(j|m)`` is the probability of recording a measurement outcome
         of ``m`` as the value ``j``. Where ``j`` and ``m`` are integer

releasenotes/notes/fix-statevector-precision-24350e9fd7368c24.yaml → releasenotes/notes/0.6/fix-statevector-precision-24350e9fd7368c24.yaml

@@ -1,7 +1,7 @@
 ---
 fixes:
   - |
-    Fixes bug in the :class:`qiskit.providers.aer.StatevectorSimulator` that
+    Fixes bug in the :class:`~qiskit.providers.aer.StatevectorSimulator` that
     caused it to always run as CPU with double-precision without SIMD/AVX2
     support even on systems with AVX2, or when single-precision or the GPU
     method was specified in the backend options.

releasenotes/notes/0.7/0.7.0-release-a6655712e304234b.yaml

@@ -0,0 +1,15 @@
+---
+prelude: >
+    This 0.7.0 release includes numerous performance improvements and
+    significant enhancements to the simulator interface, and drops support
+    for Python 3.5.
+    The main interface changes are configurable simulator backends,
+    and constructing preconfigured simulators from IBMQ backends.
+    Noise model an basis gate support has also been extended for most of the
+    Qiskit circuit library standard gates, including new support for 1 and 2-qubit
+    rotation gates.
+    Performance improvements include adding SIMD support to the density matrix
+    and unitary simulation methods, reducing the used memory and improving the
+    performance of circuits using statevector and density matrix snapshots, and
+    adding support for Kraus instructions to the gate fusion circuit optimization
+    for greatly improving the performance of noisy statevector simulations.

releasenotes/notes/basis-gates-acbc8a1a52a49413.yaml → releasenotes/notes/0.7/basis-gates-acbc8a1a52a49413.yaml

@@ -46,10 +46,27 @@ features:
     class:`~qiskit.providers.aer.StatevectorSimulator`,
     :class:`~qiskit.providers.aer.UnitarySimulator`, and
     :class:`~qiskit.providers.aer.QasmSimulator`.
+  - |
+    Adds support for 1 and 2-qubit Qiskit circuit library rotation gates
+    :class:`~qiskit.circuit.library.RXGate`, :class:`~qiskit.circuit.library.RYGate`,
+    :class:`~qiskit.circuit.library.RZGate`, :class:`~qiskit.circuit.library.RGate`,
+    :class:`~qiskit.circuit.library.RXXGate`, :class:`~qiskit.circuit.library.RYYGate`,
+    :class:`~qiskit.circuit.library.RZZGate`, :class:`~qiskit.circuit.library.RZXGate`
+    to the :class:`~qiskit.providers.aer.StatevectorSimulator`,
+    :class:`~qiskit.providers.aer.UnitarySimulator`, and the 
+    ``"statevector"`` and ``"density_matrix"`` methods of the
+    :class:`~qiskit.providers.aer.QasmSimulator`.
+  - |
+    Adds support for multi-controlled rotation gates ``"mcr"``, ``"mcrx"``,
+    ``"mcry"``, ``"mcrz"``
+    to the :class:`~qiskit.providers.aer.StatevectorSimulator`,
+    :class:`~qiskit.providers.aer.UnitarySimulator`, and the 
+    ``"statevector"`` method of the
+    :class:`~qiskit.providers.aer.QasmSimulator`.
 deprecations:
   - |
     :meth:`qiskit.providers.aer.noise.NoiseModel.set_x90_single_qubit_gates` has
     been deprecated as unrolling to custom basis gates has been added to the
     qiskit transpiler. The correct way to use an X90 based noise model is to
-    define noise on the Sqrt(X) "sx" or "rx" gate and one of the single-qubit
-    phase gates "u1", "rx", "p" in the noise model.
+    define noise on the Sqrt(X) ``"sx"`` or ``"rx"`` gate and one of the single-qubit
+    phase gates ``"u1"``, ``"rx"``, or ``"p"`` in the noise model.

releasenotes/notes/configurable-backends-a55cd6a39a0a1561.yaml → releasenotes/notes/0.7/configurable-backends-a55cd6a39a0a1561.yaml

@@ -14,6 +14,10 @@ features:
     and defaults will be configured automatically from the backend configuration, properties and
     defaults.
 
+    For example a noisy density matrix simulator backend can be constructed as
+    ``QasmSimulator(method='density_matrix', noise_model=noise_model)``, or an ideal
+    matrix product state simulator as ``QasmSimulator(method='matrix_product_state')``.
+
     A benefit is that a :class:`~qiskit.providers.aer.PulseSimulator` instance configured from
     a backend better serves as a drop-in replacement to the original backend, making it easier to
     swap in and out a simulator and real backend, e.g. when testing code on a simulator before

releasenotes/notes/deprecate-snapshot-variance-7d02188deacf9a08.yaml → releasenotes/notes/0.7/deprecate-snapshot-variance-7d02188deacf9a08.yaml

@@ -1,7 +1,7 @@
 ---
 deprecations:
   - |
-    The `variance` kwarg of Snapshot instructions has been deprecated. This
+    The ``variance`` kwarg of Snapshot instructions has been deprecated. This
     function computed the sample variance in the snapshot due to noise model
     sampling, not the variance due to measurement statistics so was often
     being used incorrectly. If noise modeling variance is required single shot

releasenotes/notes/0.7/fusion-threshold-33127b9b4e219640.yaml

@@ -0,0 +1,19 @@
+---
+upgrade:
+  - |
+    Updates gate fusion default thresholds so that gate fusion will be applied
+    to circuits with of more than 14 qubits for statevector simulations on the
+    :class:`~qiskit.providers.aer.StatevectorSimulator` and 
+    :class:`~qiskit.providers.aer.QasmSimulator`.
+    
+    For the ``"density_matrix"``
+    method of the :class:`~qiskit.providers.aer.QasmSimulator` and for the
+    :class:`~qiskit.providers.aer.UnitarySimulator` gate fusion will be applied
+    to circuits with more than 7 qubits.
+    
+    Custom qubit threshold values can be set using the ``fusion_threshold``
+    backend option ie ``backend.set_options(fusion_threshold=10)``
+  - |
+    Changes ``fusion_threshold`` backend option to apply fusion when the
+    number of qubits is above the threshold, not equal or above the threshold,
+    to match the behavior of the OpenMP qubit threshold parameter.

releasenotes/notes/kraus-noise-fusion-5577d4a38862e966.yaml → releasenotes/notes/0.7/kraus-noise-fusion-5577d4a38862e966.yaml

@@ -3,4 +3,4 @@ features:
   - |
     Improves general noisy statevector simulation performance by adding a Kraus
     method to the gate fusion circuit optimization that allows applying gate
-    fusion to noisy statevector simulations with general Kraus noise.
+    fusion to noisy statevector simulations with general Kraus noise.

releasenotes/notes/0.7/mps-apply-kraus-3cc8de65a66385ab.yaml

@@ -0,0 +1,9 @@
+---
+
+features:
+  - |
+    Adds support for general Kraus
+    :class:`~qiskit.providers.aer.noise.QauntumError` gate errors in the
+    :class:`~qiskit.providers.aer.noise.NoiseModel` to the 
+    ``"matrix_product_state"`` method of the
+    :class:`~qiskit.providers.aer.QasmSimulator`.

releasenotes/notes/0.7/mps-density-matrix-51f7d5b1ef51e746.yaml

@@ -0,0 +1,9 @@
+---
+
+features:
+  - |
+    Adds support for density matrix snapshot instruction
+    :class:`qiskit.providers.aer.extensions.SnapshotDensityMatrix` to the
+    ``"matrix_product_state"`` method of the
+    :class:`~qiskit.providers.aer.QasmSimulator`.
+