Local Braket Qubit Executor

This quantum executor accesses the local Braket quantum circuit simulator ("braket.local.qubit").

It utilizes the Pennylane plugin found here. LocalBraketQubitExecutor introduces thread-based parallelism for circuit execution on the "braket.local.qubit" device.

1. Installation

LocalBraketQubitExecutor is included in Covalent. To use it, however, you will need to install the amazon-braket-pennylane-plugin:

pip install amazon-braket-pennylane-plugin

2. Usage Example

Using LocalBraketQubitExecutor is simple:

# Local simulator
executor = ct.executor.LocalBraketQubitExecutor(
    device="default",
    shots=1024,
    num_threads=2
)

@ct.qelectron(executors=executor)
@qml.qnode(qml.device("default.qubit", wires=2, shots=1024))
def circuit(x):
    qml.IQPEmbedding(features=x, wires=[0, 1])
    qml.Hadamard(wires=1)
    return [qml.expval(qml.PauliZ(0)), qml.expval(qml.PauliZ(1))]

As a QElectron, the circuit can be called either normally or asynchronously using circuit.run_later().

Synchronous example output is below

>>> print(circuit([0.5, 0.1]))

[array(0.008), array(0.996)]

and asynchronously:

>>> x = [0.6, -1.57]

>>> # Queue jobs for all three circuit calls simultaneously on.
>>> futs = [circuit.run_later(x) for _ in range(3)]

>>> # Wait for all circuits to finish.
>>> [fut.result() for fut in futs]

[[array(-0.02), array(0.01)],
 [array(0.014), array(-0.022)],
 [array(-0.074), array(0.05)]]

3. Overview of Configuration

The LocalBraketQubitExecutor configuration is found under [qelectron.LocalBraketQubitExecutor] in the Covalent configuration file.

Config	Is Required	Default	Description
backend	No	"default"	The type of simulator backend to be used. Choices are "default", "braket_sv", "braket_dm" and "braket_ahs".

---

pydantic model covalent.executor.LocalBraketQubitExecutor

#

[source]

The local Braket executor based on the existing Pennylane local Braket qubit device.

max_jobs

maximum number of parallel jobs sent by threads on batch_submit.

shots

number of shots used to estimate quantum observables.

backend

The name of the simulator backend. Defaults to the 'default' simulator backend name.

run_kwargs

Variable length keyword arguments for braket.devices.Device.run().

Show JSON Schema

{
   "title": "LocalBraketQubitExecutor",
   "description": "The local Braket executor based on the existing Pennylane local Braket qubit device.\n\nAttributes:\n    max_jobs: maximum number of parallel jobs sent by processes on :code:`batch_submit`.\n    shots: number of shots used to estimate quantum observables.\n    backend:\n        The name of the simulator backend. Defaults to the :code:`\"default\"`\n        simulator backend name.\n    run_kwargs: Variable length keyword arguments for :code:`braket.devices.Device.run()`.",
   "type": "object",
   "properties": {
      "persist_data": {
         "title": "Persist Data",
         "default": true,
         "type": "boolean"
      },
      "qnode_device_import_path": {
         "title": "Qnode Device Import Path",
         "type": "array",
         "minItems": 2,
         "maxItems": 2,
         "items": [
            {
               "type": "string"
            },
            {
               "type": "string"
            }
         ]
      },
      "qnode_device_shots": {
         "title": "Qnode Device Shots",
         "type": "integer"
      },
      "qnode_device_wires": {
         "title": "Qnode Device Wires",
         "type": "integer"
      },
      "pennylane_active_return": {
         "title": "Pennylane Active Return",
         "type": "boolean"
      },
      "device": {
         "title": "Device",
         "default": "default.qubit",
         "type": "string"
      },
      "num_processes": {
         "title": "Num Processes",
         "default": 10,
         "type": "integer"
      },
      "max_jobs": {
         "title": "Max Jobs",
         "default": 20,
         "type": "integer"
      },
      "shots": {
         "title": "Shots",
         "type": "integer"
      },
      "backend": {
         "title": "Backend",
         "type": "string"
      },
      "run_kwargs": {
         "title": "Run Kwargs",
         "default": {},
         "type": "object"
      }
   }
}

CONFIG

extra: EXTRA = allow

field backend: str [Optional]

#

Validated by

set_name

field max_jobs: int = 20

#

Validated by

set_name

field run_kwargs: dict = {}

#

Validated by

set_name

field shots: int = None

#

Validated by

set_name

batch_submit

#

[source]

Submit qscripts for execution using num_processes-many processes.

Parameters

qscripts_list (List): a list of Pennylane style QuantumScripts

Returns

a list of futures submitted by processes.

Return Type

jobs

dict

#

[source]

Generate a dictionary representation of the model, optionally specifying which fields to include or exclude.