The local Braket device¶
The local qubit device of the PennyLane-Braket plugin runs gate-based quantum computations on the local Braket SDK. This could be either utilizing the processors of your own PC, or those of a Braket notebook instance hosted on AWS.
This device is useful for small-scale simulations in which the time of sending a job to a remote service would add an unnecessary overhead. It can also be used for rapid prototyping before running a computation on a paid-for remote service.
Usage¶
After the Braket SDK and the plugin are installed you immediately have access to the local Braket device in PennyLane.
To instantiate the local Braket simulator, simply use:
import pennylane as qml
device_local = qml.device("braket.local.qubit", wires=2) # local state vector simulator
# device_local = qml.device("braket.local.qubit", backend="default", wires=2) # local state vector simulator
# device_local = qml.device("braket.local.qubit", backend="braket_sv", wires=2) # local state vector simulator
# device_local = qml.device("braket.local.qubit", backend="braket_dm", wires=2) # local state vector simulator
You can define and evaluate quantum nodes with these devices just as you would with any other PennyLane device.
For example:
@qml.qnode(device_local)
def circuit(x, y, z):
qml.RZ(z, wires=[0])
qml.RY(y, wires=[0])
qml.RX(x, wires=[0])
qml.CNOT(wires=[0, 1])
return qml.expval(qml.PauliZ(0)), var(qml.PauliZ(1))
When executed, the circuit will perform the computation on the local machine.
>>> circuit(0.2, 0.1, 0.3)
array([0.97517033, 0.04904283])
Device options¶
You can set shots to None (default) to get exact results instead of results calculated from samples.
Supported operations¶
The operations supported by this device vary based on the operations supported by the underlying Braket device. To check the device’s supported operations, run
dev.operations
In addition to those provided by PennyLane,
the PennyLane-Braket plugin provides the following framework-specific operations, which can be imported
from braket.pennylane_plugin.ops:
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Controlled phase shift gate phasing the \(| 00 \rangle\) state. |
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Controlled phase shift gate phasing the \(| 01 \rangle\) state. |
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Controlled phase shift gate phasing the \(| 10 \rangle\) state. |
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Phase-SWAP gate. |
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IonQ native GPi gate. |
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IonQ native GPi2 gate. |
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IonQ native Mølmer-Sørenson gate. |