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Este tutorial implementa uma Rede Neural Convolucional Quântica (QCNN) simplificada, um análogo quântico proposto para uma rede neural convolucional clássica que também é translacionalmente invariável .
Este exemplo demonstra como detectar certas propriedades de uma fonte de dados quântica, como um sensor quântico ou uma simulação complexa de um dispositivo. A fonte de dados quântica sendo um estado de cluster que pode ou não ter uma excitação - o que o QCNN aprenderá a detectar (o conjunto de dados usado no artigo foi a classificação de fase SPT).
Configurar
pip install tensorflow==2.7.0
Instale o TensorFlow Quantum:
pip install tensorflow-quantum
# Update package resources to account for version changes.
import importlib, pkg_resources
importlib.reload(pkg_resources)
<module 'pkg_resources' from '/tmpfs/src/tf_docs_env/lib/python3.7/site-packages/pkg_resources/__init__.py'>
Agora importe o TensorFlow e as dependências do módulo:
import tensorflow as tf
import tensorflow_quantum as tfq
import cirq
import sympy
import numpy as np
# visualization tools
%matplotlib inline
import matplotlib.pyplot as plt
from cirq.contrib.svg import SVGCircuit
2022-02-04 12:43:45.380301: E tensorflow/stream_executor/cuda/cuda_driver.cc:271] failed call to cuInit: CUDA_ERROR_NO_DEVICE: no CUDA-capable device is detected
1. Construa um QCNN
1.1 Montar circuitos em um gráfico TensorFlow
O TensorFlow Quantum (TFQ) fornece classes de camada projetadas para construção de circuitos em grafos. Um exemplo é a camada tfq.layers.AddCircuit que herda de tf.keras.Layer . Essa camada pode ser anexada ou anexada ao lote de circuitos de entrada, conforme mostrado na figura a seguir.
O snippet a seguir usa essa camada:
qubit = cirq.GridQubit(0, 0)
# Define some circuits.
circuit1 = cirq.Circuit(cirq.X(qubit))
circuit2 = cirq.Circuit(cirq.H(qubit))
# Convert to a tensor.
input_circuit_tensor = tfq.convert_to_tensor([circuit1, circuit2])
# Define a circuit that we want to append
y_circuit = cirq.Circuit(cirq.Y(qubit))
# Instantiate our layer
y_appender = tfq.layers.AddCircuit()
# Run our circuit tensor through the layer and save the output.
output_circuit_tensor = y_appender(input_circuit_tensor, append=y_circuit)
Examine o tensor de entrada:
print(tfq.from_tensor(input_circuit_tensor))
[cirq.Circuit([
cirq.Moment(
cirq.X(cirq.GridQubit(0, 0)),
),
])
cirq.Circuit([
cirq.Moment(
cirq.H(cirq.GridQubit(0, 0)),
),
]) ]
E examine o tensor de saída:
print(tfq.from_tensor(output_circuit_tensor))
[cirq.Circuit([
cirq.Moment(
cirq.X(cirq.GridQubit(0, 0)),
),
cirq.Moment(
cirq.Y(cirq.GridQubit(0, 0)),
),
])
cirq.Circuit([
cirq.Moment(
cirq.H(cirq.GridQubit(0, 0)),
),
cirq.Moment(
cirq.Y(cirq.GridQubit(0, 0)),
),
]) ]
Embora seja possível executar os exemplos abaixo sem usar tfq.layers.AddCircuit , é uma boa oportunidade para entender como funcionalidades complexas podem ser incorporadas aos gráficos de computação do TensorFlow.
1.2 Visão geral do problema
Você preparará um estado de cluster e treinará um classificador quântico para detectar se está "excitado" ou não. O estado do cluster é altamente emaranhado, mas não necessariamente difícil para um computador clássico. Para maior clareza, este é um conjunto de dados mais simples do que o usado no artigo.
Para esta tarefa de classificação, você implementará uma arquitetura QCNN profunda do tipo MERA , pois:
- Como o QCNN, o estado do cluster em um anel é translacionalmente invariável.
- O estado do cluster é altamente emaranhado.
Essa arquitetura deve ser eficaz na redução do emaranhamento, obtendo a classificação lendo um único qubit.
Um estado de cluster "excitado" é definido como um estado de cluster que teve uma porta cirq.rx aplicada a qualquer um de seus qubits. Qconv e QPool são discutidos posteriormente neste tutorial.
1.3 Blocos de construção do TensorFlow
Uma maneira de resolver esse problema com o TensorFlow Quantum é implementar o seguinte:
- A entrada para o modelo é um tensor de circuito - um circuito vazio ou uma porta X em um qubit específico indicando uma excitação.
- Os demais componentes quânticos do modelo são construídos com camadas
tfq.layers.AddCircuit. - Para inferência é usada uma camada
tfq.layers.PQC. Isso lê \(\langle \hat{Z} \rangle\) e o compara com um rótulo de 1 para um estado excitado ou -1 para um estado não excitado.
1.4 Dados
Antes de construir seu modelo, você pode gerar seus dados. Nesse caso, serão excitações para o estado do cluster (o artigo original usa um conjunto de dados mais complicado). As excitações são representadas com portas cirq.rx Uma rotação grande o suficiente é considerada uma excitação e é rotulada como 1 e uma rotação que não é grande o suficiente é rotulada -1 e considerada não uma excitação.
def generate_data(qubits):
"""Generate training and testing data."""
n_rounds = 20 # Produces n_rounds * n_qubits datapoints.
excitations = []
labels = []
for n in range(n_rounds):
for bit in qubits:
rng = np.random.uniform(-np.pi, np.pi)
excitations.append(cirq.Circuit(cirq.rx(rng)(bit)))
labels.append(1 if (-np.pi / 2) <= rng <= (np.pi / 2) else -1)
split_ind = int(len(excitations) * 0.7)
train_excitations = excitations[:split_ind]
test_excitations = excitations[split_ind:]
train_labels = labels[:split_ind]
test_labels = labels[split_ind:]
return tfq.convert_to_tensor(train_excitations), np.array(train_labels), \
tfq.convert_to_tensor(test_excitations), np.array(test_labels)
Você pode ver que, assim como no aprendizado de máquina comum, você cria um conjunto de treinamento e teste para usar para comparar o modelo. Você pode ver rapidamente alguns pontos de dados com:
sample_points, sample_labels, _, __ = generate_data(cirq.GridQubit.rect(1, 4))
print('Input:', tfq.from_tensor(sample_points)[0], 'Output:', sample_labels[0])
print('Input:', tfq.from_tensor(sample_points)[1], 'Output:', sample_labels[1])
Input: (0, 0): ───X^0.449─── Output: 1 Input: (0, 1): ───X^-0.74─── Output: -1
1.5 Definir camadas
Agora defina as camadas mostradas na figura acima no TensorFlow.
1.5.1 Estado do cluster
A primeira etapa é definir o estado do cluster usando Cirq , uma estrutura fornecida pelo Google para programar circuitos quânticos. Como esta é uma parte estática do modelo, incorpore-a usando a funcionalidade tfq.layers.AddCircuit .
def cluster_state_circuit(bits):
"""Return a cluster state on the qubits in `bits`."""
circuit = cirq.Circuit()
circuit.append(cirq.H.on_each(bits))
for this_bit, next_bit in zip(bits, bits[1:] + [bits[0]]):
circuit.append(cirq.CZ(this_bit, next_bit))
return circuit
Exiba um circuito de estado de cluster para um retângulo de cirq.GridQubit s:
SVGCircuit(cluster_state_circuit(cirq.GridQubit.rect(1, 4)))
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1.5.2 camadas QCNN
Defina as camadas que compõem o modelo usando o papel Cong e Lukin QCNN . Existem alguns pré-requisitos:
- As matrizes unitárias parametrizadas de um e dois qubits do artigo de Tucci .
- Uma operação geral de pool de dois qubits parametrizada.
def one_qubit_unitary(bit, symbols):
"""Make a Cirq circuit enacting a rotation of the bloch sphere about the X,
Y and Z axis, that depends on the values in `symbols`.
"""
return cirq.Circuit(
cirq.X(bit)**symbols[0],
cirq.Y(bit)**symbols[1],
cirq.Z(bit)**symbols[2])
def two_qubit_unitary(bits, symbols):
"""Make a Cirq circuit that creates an arbitrary two qubit unitary."""
circuit = cirq.Circuit()
circuit += one_qubit_unitary(bits[0], symbols[0:3])
circuit += one_qubit_unitary(bits[1], symbols[3:6])
circuit += [cirq.ZZ(*bits)**symbols[6]]
circuit += [cirq.YY(*bits)**symbols[7]]
circuit += [cirq.XX(*bits)**symbols[8]]
circuit += one_qubit_unitary(bits[0], symbols[9:12])
circuit += one_qubit_unitary(bits[1], symbols[12:])
return circuit
def two_qubit_pool(source_qubit, sink_qubit, symbols):
"""Make a Cirq circuit to do a parameterized 'pooling' operation, which
attempts to reduce entanglement down from two qubits to just one."""
pool_circuit = cirq.Circuit()
sink_basis_selector = one_qubit_unitary(sink_qubit, symbols[0:3])
source_basis_selector = one_qubit_unitary(source_qubit, symbols[3:6])
pool_circuit.append(sink_basis_selector)
pool_circuit.append(source_basis_selector)
pool_circuit.append(cirq.CNOT(control=source_qubit, target=sink_qubit))
pool_circuit.append(sink_basis_selector**-1)
return pool_circuit
Para ver o que você criou, imprima o circuito unitário de um qubit:
SVGCircuit(one_qubit_unitary(cirq.GridQubit(0, 0), sympy.symbols('x0:3')))
E o circuito unitário de dois qubits:
SVGCircuit(two_qubit_unitary(cirq.GridQubit.rect(1, 2), sympy.symbols('x0:15')))
E o circuito de pool de dois qubits:
SVGCircuit(two_qubit_pool(*cirq.GridQubit.rect(1, 2), sympy.symbols('x0:6')))
1.5.2.1 Convolução quântica
Como no artigo de Cong e Lukin , defina a convolução quântica 1D como a aplicação de uma unidade parametrizada de dois qubits a cada par de qubits adjacentes com um passo de um.
def quantum_conv_circuit(bits, symbols):
"""Quantum Convolution Layer following the above diagram.
Return a Cirq circuit with the cascade of `two_qubit_unitary` applied
to all pairs of qubits in `bits` as in the diagram above.
"""
circuit = cirq.Circuit()
for first, second in zip(bits[0::2], bits[1::2]):
circuit += two_qubit_unitary([first, second], symbols)
for first, second in zip(bits[1::2], bits[2::2] + [bits[0]]):
circuit += two_qubit_unitary([first, second], symbols)
return circuit
Exiba o circuito (muito horizontal):
SVGCircuit(
quantum_conv_circuit(cirq.GridQubit.rect(1, 8), sympy.symbols('x0:15')))
1.5.2.2 Agrupamento quântico
Uma camada de pool quântico agrupa de qubits l10n \(N\) para qubits \(\frac{N}{2}\) usando o pool de dois qubits definido acima.
def quantum_pool_circuit(source_bits, sink_bits, symbols):
"""A layer that specifies a quantum pooling operation.
A Quantum pool tries to learn to pool the relevant information from two
qubits onto 1.
"""
circuit = cirq.Circuit()
for source, sink in zip(source_bits, sink_bits):
circuit += two_qubit_pool(source, sink, symbols)
return circuit
Examine um circuito de componente de pooling:
test_bits = cirq.GridQubit.rect(1, 8)
SVGCircuit(
quantum_pool_circuit(test_bits[:4], test_bits[4:], sympy.symbols('x0:6')))
1.6 Definição do modelo
Agora use as camadas definidas para construir uma CNN puramente quântica. Comece com oito qubits, agrupe até um e, em seguida, meça \(\langle \hat{Z} \rangle\).
def create_model_circuit(qubits):
"""Create sequence of alternating convolution and pooling operators
which gradually shrink over time."""
model_circuit = cirq.Circuit()
symbols = sympy.symbols('qconv0:63')
# Cirq uses sympy.Symbols to map learnable variables. TensorFlow Quantum
# scans incoming circuits and replaces these with TensorFlow variables.
model_circuit += quantum_conv_circuit(qubits, symbols[0:15])
model_circuit += quantum_pool_circuit(qubits[:4], qubits[4:],
symbols[15:21])
model_circuit += quantum_conv_circuit(qubits[4:], symbols[21:36])
model_circuit += quantum_pool_circuit(qubits[4:6], qubits[6:],
symbols[36:42])
model_circuit += quantum_conv_circuit(qubits[6:], symbols[42:57])
model_circuit += quantum_pool_circuit([qubits[6]], [qubits[7]],
symbols[57:63])
return model_circuit
# Create our qubits and readout operators in Cirq.
cluster_state_bits = cirq.GridQubit.rect(1, 8)
readout_operators = cirq.Z(cluster_state_bits[-1])
# Build a sequential model enacting the logic in 1.3 of this notebook.
# Here you are making the static cluster state prep as a part of the AddCircuit and the
# "quantum datapoints" are coming in the form of excitation
excitation_input = tf.keras.Input(shape=(), dtype=tf.dtypes.string)
cluster_state = tfq.layers.AddCircuit()(
excitation_input, prepend=cluster_state_circuit(cluster_state_bits))
quantum_model = tfq.layers.PQC(create_model_circuit(cluster_state_bits),
readout_operators)(cluster_state)
qcnn_model = tf.keras.Model(inputs=[excitation_input], outputs=[quantum_model])
# Show the keras plot of the model
tf.keras.utils.plot_model(qcnn_model,
show_shapes=True,
show_layer_names=False,
dpi=70)
1.7 Treine o modelo
Treine o modelo em todo o lote para simplificar este exemplo.
# Generate some training data.
train_excitations, train_labels, test_excitations, test_labels = generate_data(
cluster_state_bits)
# Custom accuracy metric.
@tf.function
def custom_accuracy(y_true, y_pred):
y_true = tf.squeeze(y_true)
y_pred = tf.map_fn(lambda x: 1.0 if x >= 0 else -1.0, y_pred)
return tf.keras.backend.mean(tf.keras.backend.equal(y_true, y_pred))
qcnn_model.compile(optimizer=tf.keras.optimizers.Adam(learning_rate=0.02),
loss=tf.losses.mse,
metrics=[custom_accuracy])
history = qcnn_model.fit(x=train_excitations,
y=train_labels,
batch_size=16,
epochs=25,
verbose=1,
validation_data=(test_excitations, test_labels))
Epoch 1/25 7/7 [==============================] - 2s 176ms/step - loss: 0.8961 - custom_accuracy: 0.7143 - val_loss: 0.8012 - val_custom_accuracy: 0.7500 Epoch 2/25 7/7 [==============================] - 1s 140ms/step - loss: 0.7736 - custom_accuracy: 0.7946 - val_loss: 0.7355 - val_custom_accuracy: 0.8542 Epoch 3/25 7/7 [==============================] - 1s 138ms/step - loss: 0.7319 - custom_accuracy: 0.8393 - val_loss: 0.7045 - val_custom_accuracy: 0.8125 Epoch 4/25 7/7 [==============================] - 1s 137ms/step - loss: 0.6976 - custom_accuracy: 0.8482 - val_loss: 0.6829 - val_custom_accuracy: 0.8333 Epoch 5/25 7/7 [==============================] - 1s 143ms/step - loss: 0.6696 - custom_accuracy: 0.8750 - val_loss: 0.6749 - val_custom_accuracy: 0.7917 Epoch 6/25 7/7 [==============================] - 1s 137ms/step - loss: 0.6631 - custom_accuracy: 0.8750 - val_loss: 0.6718 - val_custom_accuracy: 0.7917 Epoch 7/25 7/7 [==============================] - 1s 135ms/step - loss: 0.6536 - custom_accuracy: 0.8929 - val_loss: 0.6638 - val_custom_accuracy: 0.8750 Epoch 8/25 7/7 [==============================] - 1s 141ms/step - loss: 0.6376 - custom_accuracy: 0.8750 - val_loss: 0.6311 - val_custom_accuracy: 0.8542 Epoch 9/25 7/7 [==============================] - 1s 137ms/step - loss: 0.6208 - custom_accuracy: 0.8750 - val_loss: 0.5995 - val_custom_accuracy: 0.8542 Epoch 10/25 7/7 [==============================] - 1s 134ms/step - loss: 0.5887 - custom_accuracy: 0.8661 - val_loss: 0.5655 - val_custom_accuracy: 0.8333 Epoch 11/25 7/7 [==============================] - 1s 144ms/step - loss: 0.5796 - custom_accuracy: 0.8482 - val_loss: 0.5681 - val_custom_accuracy: 0.8333 Epoch 12/25 7/7 [==============================] - 1s 143ms/step - loss: 0.5630 - custom_accuracy: 0.7946 - val_loss: 0.5179 - val_custom_accuracy: 0.8333 Epoch 13/25 7/7 [==============================] - 1s 137ms/step - loss: 0.5405 - custom_accuracy: 0.8304 - val_loss: 0.5003 - val_custom_accuracy: 0.8333 Epoch 14/25 7/7 [==============================] - 1s 138ms/step - loss: 0.5259 - custom_accuracy: 0.8036 - val_loss: 0.4787 - val_custom_accuracy: 0.8333 Epoch 15/25 7/7 [==============================] - 1s 137ms/step - loss: 0.5077 - custom_accuracy: 0.8482 - val_loss: 0.4741 - val_custom_accuracy: 0.8125 Epoch 16/25 7/7 [==============================] - 1s 136ms/step - loss: 0.5082 - custom_accuracy: 0.8214 - val_loss: 0.4739 - val_custom_accuracy: 0.8125 Epoch 17/25 7/7 [==============================] - 1s 137ms/step - loss: 0.5138 - custom_accuracy: 0.8214 - val_loss: 0.4859 - val_custom_accuracy: 0.8750 Epoch 18/25 7/7 [==============================] - 1s 133ms/step - loss: 0.5073 - custom_accuracy: 0.8304 - val_loss: 0.4879 - val_custom_accuracy: 0.8333 Epoch 19/25 7/7 [==============================] - 1s 138ms/step - loss: 0.5084 - custom_accuracy: 0.8304 - val_loss: 0.4745 - val_custom_accuracy: 0.8542 Epoch 20/25 7/7 [==============================] - 1s 139ms/step - loss: 0.5057 - custom_accuracy: 0.8571 - val_loss: 0.4702 - val_custom_accuracy: 0.8333 Epoch 21/25 7/7 [==============================] - 1s 135ms/step - loss: 0.4939 - custom_accuracy: 0.8304 - val_loss: 0.4734 - val_custom_accuracy: 0.8750 Epoch 22/25 7/7 [==============================] - 1s 138ms/step - loss: 0.4942 - custom_accuracy: 0.8750 - val_loss: 0.4725 - val_custom_accuracy: 0.8750 Epoch 23/25 7/7 [==============================] - 1s 140ms/step - loss: 0.4982 - custom_accuracy: 0.9107 - val_loss: 0.4695 - val_custom_accuracy: 0.8958 Epoch 24/25 7/7 [==============================] - 1s 135ms/step - loss: 0.4936 - custom_accuracy: 0.8661 - val_loss: 0.4731 - val_custom_accuracy: 0.8750 Epoch 25/25 7/7 [==============================] - 1s 136ms/step - loss: 0.4866 - custom_accuracy: 0.8571 - val_loss: 0.4631 - val_custom_accuracy: 0.8958
plt.plot(history.history['loss'][1:], label='Training')
plt.plot(history.history['val_loss'][1:], label='Validation')
plt.title('Training a Quantum CNN to Detect Excited Cluster States')
plt.xlabel('Epochs')
plt.ylabel('Loss')
plt.legend()
plt.show()
2. Modelos híbridos
Você não precisa ir de oito qubits para um qubit usando convolução quântica – você poderia ter feito uma ou duas rodadas de convolução quântica e alimentado os resultados em uma rede neural clássica. Esta seção explora modelos híbridos quânticos-clássicos.
2.1 Modelo híbrido com um único filtro quântico
Aplique uma camada de convolução quântica, lendo \(\langle \hat{Z}_n \rangle\) em todos os bits, seguido por uma rede neural densamente conectada.
2.1.1 Definição do modelo
# 1-local operators to read out
readouts = [cirq.Z(bit) for bit in cluster_state_bits[4:]]
def multi_readout_model_circuit(qubits):
"""Make a model circuit with less quantum pool and conv operations."""
model_circuit = cirq.Circuit()
symbols = sympy.symbols('qconv0:21')
model_circuit += quantum_conv_circuit(qubits, symbols[0:15])
model_circuit += quantum_pool_circuit(qubits[:4], qubits[4:],
symbols[15:21])
return model_circuit
# Build a model enacting the logic in 2.1 of this notebook.
excitation_input_dual = tf.keras.Input(shape=(), dtype=tf.dtypes.string)
cluster_state_dual = tfq.layers.AddCircuit()(
excitation_input_dual, prepend=cluster_state_circuit(cluster_state_bits))
quantum_model_dual = tfq.layers.PQC(
multi_readout_model_circuit(cluster_state_bits),
readouts)(cluster_state_dual)
d1_dual = tf.keras.layers.Dense(8)(quantum_model_dual)
d2_dual = tf.keras.layers.Dense(1)(d1_dual)
hybrid_model = tf.keras.Model(inputs=[excitation_input_dual], outputs=[d2_dual])
# Display the model architecture
tf.keras.utils.plot_model(hybrid_model,
show_shapes=True,
show_layer_names=False,
dpi=70)
2.1.2 Treinar o modelo
hybrid_model.compile(optimizer=tf.keras.optimizers.Adam(learning_rate=0.02),
loss=tf.losses.mse,
metrics=[custom_accuracy])
hybrid_history = hybrid_model.fit(x=train_excitations,
y=train_labels,
batch_size=16,
epochs=25,
verbose=1,
validation_data=(test_excitations,
test_labels))
Epoch 1/25 7/7 [==============================] - 1s 113ms/step - loss: 0.9848 - custom_accuracy: 0.5179 - val_loss: 0.9635 - val_custom_accuracy: 0.5417 Epoch 2/25 7/7 [==============================] - 1s 86ms/step - loss: 0.8095 - custom_accuracy: 0.6339 - val_loss: 0.6800 - val_custom_accuracy: 0.7083 Epoch 3/25 7/7 [==============================] - 1s 85ms/step - loss: 0.4045 - custom_accuracy: 0.9375 - val_loss: 0.3342 - val_custom_accuracy: 0.8750 Epoch 4/25 7/7 [==============================] - 1s 86ms/step - loss: 0.2308 - custom_accuracy: 0.9643 - val_loss: 0.2027 - val_custom_accuracy: 0.9792 Epoch 5/25 7/7 [==============================] - 1s 84ms/step - loss: 0.2232 - custom_accuracy: 0.9554 - val_loss: 0.1761 - val_custom_accuracy: 1.0000 Epoch 6/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1760 - custom_accuracy: 0.9821 - val_loss: 0.2541 - val_custom_accuracy: 0.9167 Epoch 7/25 7/7 [==============================] - 1s 85ms/step - loss: 0.1919 - custom_accuracy: 0.9643 - val_loss: 0.1967 - val_custom_accuracy: 0.9792 Epoch 8/25 7/7 [==============================] - 1s 83ms/step - loss: 0.1892 - custom_accuracy: 0.9554 - val_loss: 0.1870 - val_custom_accuracy: 0.9792 Epoch 9/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1777 - custom_accuracy: 0.9911 - val_loss: 0.2208 - val_custom_accuracy: 0.9583 Epoch 10/25 7/7 [==============================] - 1s 83ms/step - loss: 0.1728 - custom_accuracy: 0.9732 - val_loss: 0.2147 - val_custom_accuracy: 0.9583 Epoch 11/25 7/7 [==============================] - 1s 85ms/step - loss: 0.1704 - custom_accuracy: 0.9732 - val_loss: 0.1810 - val_custom_accuracy: 0.9792 Epoch 12/25 7/7 [==============================] - 1s 85ms/step - loss: 0.1739 - custom_accuracy: 0.9732 - val_loss: 0.2038 - val_custom_accuracy: 0.9792 Epoch 13/25 7/7 [==============================] - 1s 81ms/step - loss: 0.1705 - custom_accuracy: 0.9732 - val_loss: 0.1855 - val_custom_accuracy: 0.9792 Epoch 14/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1788 - custom_accuracy: 0.9643 - val_loss: 0.2152 - val_custom_accuracy: 0.9583 Epoch 15/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1760 - custom_accuracy: 0.9732 - val_loss: 0.1994 - val_custom_accuracy: 1.0000 Epoch 16/25 7/7 [==============================] - 1s 83ms/step - loss: 0.1737 - custom_accuracy: 0.9732 - val_loss: 0.2035 - val_custom_accuracy: 0.9792 Epoch 17/25 7/7 [==============================] - 1s 82ms/step - loss: 0.1749 - custom_accuracy: 0.9911 - val_loss: 0.1983 - val_custom_accuracy: 0.9583 Epoch 18/25 7/7 [==============================] - 1s 83ms/step - loss: 0.1875 - custom_accuracy: 0.9732 - val_loss: 0.1916 - val_custom_accuracy: 0.9583 Epoch 19/25 7/7 [==============================] - 1s 82ms/step - loss: 0.1605 - custom_accuracy: 0.9732 - val_loss: 0.1782 - val_custom_accuracy: 0.9792 Epoch 20/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1668 - custom_accuracy: 0.9911 - val_loss: 0.2276 - val_custom_accuracy: 0.9583 Epoch 21/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1700 - custom_accuracy: 0.9911 - val_loss: 0.2080 - val_custom_accuracy: 0.9583 Epoch 22/25 7/7 [==============================] - 1s 83ms/step - loss: 0.1621 - custom_accuracy: 0.9732 - val_loss: 0.1851 - val_custom_accuracy: 0.9375 Epoch 23/25 7/7 [==============================] - 1s 84ms/step - loss: 0.1695 - custom_accuracy: 0.9911 - val_loss: 0.1882 - val_custom_accuracy: 0.9792 Epoch 24/25 7/7 [==============================] - 1s 82ms/step - loss: 0.1583 - custom_accuracy: 0.9911 - val_loss: 0.2017 - val_custom_accuracy: 0.9583 Epoch 25/25 7/7 [==============================] - 1s 83ms/step - loss: 0.1557 - custom_accuracy: 0.9911 - val_loss: 0.1907 - val_custom_accuracy: 0.9792
plt.plot(history.history['val_custom_accuracy'], label='QCNN')
plt.plot(hybrid_history.history['val_custom_accuracy'], label='Hybrid CNN')
plt.title('Quantum vs Hybrid CNN performance')
plt.xlabel('Epochs')
plt.legend()
plt.ylabel('Validation Accuracy')
plt.show()
Como você pode ver, com uma assistência clássica muito modesta, o modelo híbrido geralmente converge mais rápido do que a versão puramente quântica.
2.2 Convolução híbrida com vários filtros quânticos
Agora vamos tentar uma arquitetura que usa várias convoluções quânticas e uma rede neural clássica para combiná-las.
2.2.1 Definição do modelo
excitation_input_multi = tf.keras.Input(shape=(), dtype=tf.dtypes.string)
cluster_state_multi = tfq.layers.AddCircuit()(
excitation_input_multi, prepend=cluster_state_circuit(cluster_state_bits))
# apply 3 different filters and measure expectation values
quantum_model_multi1 = tfq.layers.PQC(
multi_readout_model_circuit(cluster_state_bits),
readouts)(cluster_state_multi)
quantum_model_multi2 = tfq.layers.PQC(
multi_readout_model_circuit(cluster_state_bits),
readouts)(cluster_state_multi)
quantum_model_multi3 = tfq.layers.PQC(
multi_readout_model_circuit(cluster_state_bits),
readouts)(cluster_state_multi)
# concatenate outputs and feed into a small classical NN
concat_out = tf.keras.layers.concatenate(
[quantum_model_multi1, quantum_model_multi2, quantum_model_multi3])
dense_1 = tf.keras.layers.Dense(8)(concat_out)
dense_2 = tf.keras.layers.Dense(1)(dense_1)
multi_qconv_model = tf.keras.Model(inputs=[excitation_input_multi],
outputs=[dense_2])
# Display the model architecture
tf.keras.utils.plot_model(multi_qconv_model,
show_shapes=True,
show_layer_names=True,
dpi=70)
2.2.2 Treinar o modelo
multi_qconv_model.compile(
optimizer=tf.keras.optimizers.Adam(learning_rate=0.02),
loss=tf.losses.mse,
metrics=[custom_accuracy])
multi_qconv_history = multi_qconv_model.fit(x=train_excitations,
y=train_labels,
batch_size=16,
epochs=25,
verbose=1,
validation_data=(test_excitations,
test_labels))
Epoch 1/25 7/7 [==============================] - 2s 143ms/step - loss: 0.9425 - custom_accuracy: 0.6429 - val_loss: 0.8120 - val_custom_accuracy: 0.7083 Epoch 2/25 7/7 [==============================] - 1s 109ms/step - loss: 0.5778 - custom_accuracy: 0.7946 - val_loss: 0.5920 - val_custom_accuracy: 0.7500 Epoch 3/25 7/7 [==============================] - 1s 103ms/step - loss: 0.4954 - custom_accuracy: 0.9018 - val_loss: 0.4568 - val_custom_accuracy: 0.7708 Epoch 4/25 7/7 [==============================] - 1s 95ms/step - loss: 0.2855 - custom_accuracy: 0.9196 - val_loss: 0.2792 - val_custom_accuracy: 0.9375 Epoch 5/25 7/7 [==============================] - 1s 93ms/step - loss: 0.1902 - custom_accuracy: 0.9821 - val_loss: 0.2212 - val_custom_accuracy: 0.9375 Epoch 6/25 7/7 [==============================] - 1s 94ms/step - loss: 0.1685 - custom_accuracy: 0.9821 - val_loss: 0.2341 - val_custom_accuracy: 0.9583 Epoch 7/25 7/7 [==============================] - 1s 104ms/step - loss: 0.1671 - custom_accuracy: 0.9911 - val_loss: 0.2062 - val_custom_accuracy: 0.9792 Epoch 8/25 7/7 [==============================] - 1s 97ms/step - loss: 0.1511 - custom_accuracy: 0.9821 - val_loss: 0.2096 - val_custom_accuracy: 0.9792 Epoch 9/25 7/7 [==============================] - 1s 96ms/step - loss: 0.1432 - custom_accuracy: 0.9911 - val_loss: 0.2330 - val_custom_accuracy: 0.9375 Epoch 10/25 7/7 [==============================] - 1s 92ms/step - loss: 0.1668 - custom_accuracy: 0.9821 - val_loss: 0.2344 - val_custom_accuracy: 0.9583 Epoch 11/25 7/7 [==============================] - 1s 106ms/step - loss: 0.1893 - custom_accuracy: 0.9732 - val_loss: 0.2148 - val_custom_accuracy: 0.9583 Epoch 12/25 7/7 [==============================] - 1s 104ms/step - loss: 0.1857 - custom_accuracy: 0.9732 - val_loss: 0.2739 - val_custom_accuracy: 0.9583 Epoch 13/25 7/7 [==============================] - 1s 106ms/step - loss: 0.1748 - custom_accuracy: 0.9732 - val_loss: 0.2366 - val_custom_accuracy: 0.9583 Epoch 14/25 7/7 [==============================] - 1s 103ms/step - loss: 0.1515 - custom_accuracy: 0.9821 - val_loss: 0.2012 - val_custom_accuracy: 0.9583 Epoch 15/25 7/7 [==============================] - 1s 100ms/step - loss: 0.1552 - custom_accuracy: 0.9911 - val_loss: 0.2404 - val_custom_accuracy: 0.9375 Epoch 16/25 7/7 [==============================] - 1s 97ms/step - loss: 0.1572 - custom_accuracy: 0.9911 - val_loss: 0.2779 - val_custom_accuracy: 0.9375 Epoch 17/25 7/7 [==============================] - 1s 100ms/step - loss: 0.1546 - custom_accuracy: 0.9821 - val_loss: 0.2104 - val_custom_accuracy: 0.9583 Epoch 18/25 7/7 [==============================] - 1s 102ms/step - loss: 0.1418 - custom_accuracy: 0.9911 - val_loss: 0.2647 - val_custom_accuracy: 0.9583 Epoch 19/25 7/7 [==============================] - 1s 98ms/step - loss: 0.1590 - custom_accuracy: 0.9732 - val_loss: 0.2154 - val_custom_accuracy: 0.9583 Epoch 20/25 7/7 [==============================] - 1s 104ms/step - loss: 0.1363 - custom_accuracy: 1.0000 - val_loss: 0.2470 - val_custom_accuracy: 0.9375 Epoch 21/25 7/7 [==============================] - 1s 100ms/step - loss: 0.1442 - custom_accuracy: 0.9821 - val_loss: 0.2383 - val_custom_accuracy: 0.9375 Epoch 22/25 7/7 [==============================] - 1s 99ms/step - loss: 0.1415 - custom_accuracy: 0.9911 - val_loss: 0.2324 - val_custom_accuracy: 0.9583 Epoch 23/25 7/7 [==============================] - 1s 97ms/step - loss: 0.1424 - custom_accuracy: 0.9821 - val_loss: 0.2188 - val_custom_accuracy: 0.9583 Epoch 24/25 7/7 [==============================] - 1s 100ms/step - loss: 0.1417 - custom_accuracy: 0.9821 - val_loss: 0.2340 - val_custom_accuracy: 0.9375 Epoch 25/25 7/7 [==============================] - 1s 103ms/step - loss: 0.1471 - custom_accuracy: 0.9732 - val_loss: 0.2252 - val_custom_accuracy: 0.9583
plt.plot(history.history['val_custom_accuracy'][:25], label='QCNN')
plt.plot(hybrid_history.history['val_custom_accuracy'][:25], label='Hybrid CNN')
plt.plot(multi_qconv_history.history['val_custom_accuracy'][:25],
label='Hybrid CNN \n Multiple Quantum Filters')
plt.title('Quantum vs Hybrid CNN performance')
plt.xlabel('Epochs')
plt.legend()
plt.ylabel('Validation Accuracy')
plt.show()
