Hello! When I try to use lightning.gpu simulator instead of default.qubit simulator or lightning.qubit simulator, the execution results are strange. What could be the cause?
I am using Google Colab.
The code is below.
I referred to this site.
pip install pennylane pip install cuquantum-python pip install pennylane-lightning[gpu]
import pennylane as qml from pennylane import qaoa from networkx import Graph # Defines the wires and the graph on which MaxCut is being performed wires = range(3) graph = Graph([(0, 1), (1, 2), (2, 0)])
# Defines the QAOA cost and mixer Hamiltonians cost_h, mixer_h = qaoa.maxcut(graph)
# Defines a layer of the QAOA ansatz from the cost and mixer Hamiltonians def qaoa_layer(gamma, alpha): qaoa.cost_layer(gamma, cost_h) qaoa.mixer_layer(alpha, mixer_h)
# Repeatedly applies layers of the QAOA ansatz def circuit(params, **kwargs): for w in wires: qml.Hadamard(wires=w) qml.layer(qaoa_layer, 2, params, params)
# Defines the device and the QAOA cost function dev = qml.device('lightning.gpu', wires=len(wires)) cost_function = qml.ExpvalCost(circuit, cost_h, dev)
print(cost_function([[1, 1], [1, 1]]))
In case of ‘default.qubit’
In case of ‘lightning.qubit’
In case of ‘lightning.gpu’