def test_ugates_cirq():
c1 = Circuit(3)
c1.add(gates.RX(0, 0.1))
c1.add(gates.RZ(1, 0.4))
c1.add(gates.U2(2, 0.5, 0.6))
final_state_c1 = c1()
c2 = circuit_from_qasm(c1.to_qasm())
c2depth = len(cirq.Circuit(c2.all_operations()))
assert c1.depth == c2depth
final_state_c2 = cirq.Simulator().simulate(c2).final_state
np.testing.assert_allclose(final_state_c1, final_state_c2, atol=_atol)
c3 = Circuit.from_qasm(c2.to_qasm())
assert c3.depth == c2depth
final_state_c3 = c3()
np.testing.assert_allclose(final_state_c3, final_state_c2, atol=_atol)
c1 = Circuit(3)
c1.add(gates.RX(0, 0.1))
c1.add(gates.RZ(1, 0.4))
c1.add(gates.U2(2, 0.5, 0.6))
c1.add(gates.CU3(2, 1, 0.2, 0.3, 0.4))
# catches unknown gate "cu3"
with pytest.raises(exception.QasmException):
c2 = circuit_from_qasm(c1.to_qasm())
def test_set_parameters_with_gate_fusion(backend, accelerators):
"""Check updating parameters of fused circuit."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
params = np.random.random(9)
c = Circuit(5, accelerators)
c.add(gates.RX(0, theta=params[0]))
c.add(gates.RY(1, theta=params[1]))
c.add(gates.CZ(0, 1))
c.add(gates.RX(2, theta=params[2]))
c.add(gates.RY(3, theta=params[3]))
c.add(gates.fSim(2, 3, theta=params[4], phi=params[5]))
c.add(gates.RX(4, theta=params[6]))
c.add(gates.RZ(0, theta=params[7]))
c.add(gates.RZ(1, theta=params[8]))
fused_c = c.fuse()
np.testing.assert_allclose(c(), fused_c())
new_params = np.random.random(9)
new_params_list = list(new_params[:4])
new_params_list.append((new_params[4], new_params[5]))
new_params_list.extend(new_params[6:])
c.set_parameters(new_params_list)
fused_c.set_parameters(new_params_list)
np.testing.assert_allclose(c(), fused_c())
qibo.set_backend(original_backend)
def test_ugates_cirq(backend):
import qibo
original_backend = qibo.get_backend()
qibo.set_backend(backend)
c1 = Circuit(3)
c1.add(gates.RX(0, 0.1))
c1.add(gates.RZ(1, 0.4))
c1.add(gates.U2(2, 0.5, 0.6))
final_state_c1 = c1()
c2 = circuit_from_qasm(c1.to_qasm())
c2depth = len(cirq.Circuit(c2.all_operations()))
assert c1.depth == c2depth
final_state_c2 = cirq.Simulator().simulate(c2).final_state_vector # pylint: disable=no-member
np.testing.assert_allclose(final_state_c1, final_state_c2, atol=_atol)
c3 = Circuit.from_qasm(c2.to_qasm())
assert c3.depth == c2depth
final_state_c3 = c3()
np.testing.assert_allclose(final_state_c3, final_state_c2, atol=_atol)
c1 = Circuit(3)
c1.add(gates.RX(0, 0.1))
c1.add(gates.RZ(1, 0.4))
c1.add(gates.U2(2, 0.5, 0.6))
c1.add(gates.CU3(2, 1, 0.2, 0.3, 0.4))
# catches unknown gate "cu3"
with pytest.raises(exception.QasmException):
c2 = circuit_from_qasm(c1.to_qasm())
qibo.set_backend(original_backend)
def test_circuit_set_parameters_with_dictionary(backend, accelerators):
"""Check updating parameters of circuit with list."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
c = Circuit(3, accelerators)
c.add(gates.X(0))
c.add(gates.X(2))
c.add(gates.U1(0, theta=0))
c.add(gates.RZ(1, theta=0))
c.add(gates.CZ(1, 2))
c.add(gates.CU1(0, 2, theta=0))
c.add(gates.H(2))
c.add(gates.Unitary(np.eye(2), 1))
final_state = c()
params = [0.123, 0.456, 0.789, np.random.random((2, 2))]
target_c = Circuit(3, accelerators)
target_c.add(gates.X(0))
target_c.add(gates.X(2))
target_c.add(gates.U1(0, theta=params[0]))
target_c.add(gates.RZ(1, theta=params[1]))
target_c.add(gates.CZ(1, 2))
target_c.add(gates.CU1(0, 2, theta=params[2]))
target_c.add(gates.H(2))
target_c.add(gates.Unitary(params[3], 1))
param_dict = {c.queue[i]: p for i, p in zip([2, 3, 5, 7], params)}
c.set_parameters(param_dict)
np.testing.assert_allclose(c(), target_c())
qibo.set_backend(original_backend)
def ansatz_Fourier_2D(layers, qubits=1):
"""
3 parameters per layer: Ry(wx + a), Rz(b)
"""
circuit = models.Circuit(qubits)
for _ in range(layers):
circuit.add(gates.RY(0, theta=0))
circuit.add(gates.RZ(0, theta=0))
circuit.add(gates.RY(0, theta=0))
circuit.add(gates.RZ(0, theta=0))
def rotation(theta, x):
p = circuit.get_parameters()
i = 0
j = 0
for l in range(layers):
p[i] = theta[j]
p[i + 1] = theta[j + 1] + theta[j + 2:j + 4] @ x
p[i + 2] = theta[j + 4]
p[i + 3] = theta[j + 5]
i += 4
j += 6
return p
nparams = 6 * (layers)
return circuit, rotation, nparams
def test_set_parameters_with_gate_fusion(backend, trainable):
"""Check updating parameters of fused circuit."""
params = np.random.random(9)
c = Circuit(5)
c.add(gates.RX(0, theta=params[0], trainable=trainable))
c.add(gates.RY(1, theta=params[1]))
c.add(gates.CZ(0, 1))
c.add(gates.RX(2, theta=params[2]))
c.add(gates.RY(3, theta=params[3], trainable=trainable))
c.add(gates.fSim(2, 3, theta=params[4], phi=params[5]))
c.add(gates.RX(4, theta=params[6]))
c.add(gates.RZ(0, theta=params[7], trainable=trainable))
c.add(gates.RZ(1, theta=params[8]))
fused_c = c.fuse()
final_state = fused_c()
target_state = c()
K.assert_allclose(final_state, target_state)
if trainable:
new_params = np.random.random(9)
new_params_list = list(new_params[:4])
new_params_list.append((new_params[4], new_params[5]))
new_params_list.extend(new_params[6:])
else:
new_params = np.random.random(9)
new_params_list = list(new_params[1:3])
new_params_list.append((new_params[4], new_params[5]))
new_params_list.append(new_params[6])
new_params_list.append(new_params[8])
c.set_parameters(new_params_list)
fused_c.set_parameters(new_params_list)
K.assert_allclose(c(), fused_c())
def test_circuit_set_parameters_with_dictionary(backend, accelerators,
trainable):
"""Check updating parameters of circuit with list."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
params = [0.123, 0.456, 0.789, np.random.random((2, 2))]
c1 = Circuit(3, accelerators)
c1.add(gates.X(0))
c1.add(gates.X(2))
if trainable:
c1.add(gates.U1(0, theta=0, trainable=trainable))
else:
c1.add(gates.U1(0, theta=params[0], trainable=trainable))
c2 = Circuit(3, accelerators)
c2.add(gates.RZ(1, theta=0))
c2.add(gates.CZ(1, 2))
c2.add(gates.CU1(0, 2, theta=0))
c2.add(gates.H(2))
if trainable:
c2.add(gates.Unitary(np.eye(2), 1, trainable=trainable))
else:
c2.add(gates.Unitary(params[3], 1, trainable=trainable))
c = c1 + c2
final_state = c()
target_c = Circuit(3, accelerators)
target_c.add(gates.X(0))
target_c.add(gates.X(2))
target_c.add(gates.U1(0, theta=params[0]))
target_c.add(gates.RZ(1, theta=params[1]))
target_c.add(gates.CZ(1, 2))
target_c.add(gates.CU1(0, 2, theta=params[2]))
target_c.add(gates.H(2))
target_c.add(gates.Unitary(params[3], 1))
if trainable:
params_dict = {c.queue[i]: p for i, p in zip([2, 3, 5, 7], params)}
else:
params_dict = {c.queue[3]: params[1], c.queue[5]: params[2]}
c.set_parameters(params_dict)
np.testing.assert_allclose(c(), target_c())
# test not passing all parametrized gates
target_c = Circuit(3, accelerators)
target_c.add(gates.X(0))
target_c.add(gates.X(2))
target_c.add(gates.U1(0, theta=params[0]))
target_c.add(gates.RZ(1, theta=params[1]))
target_c.add(gates.CZ(1, 2))
target_c.add(gates.CU1(0, 2, theta=0.7891))
target_c.add(gates.H(2))
target_c.add(gates.Unitary(params[3], 1))
c.set_parameters({c.queue[5]: 0.7891})
np.testing.assert_allclose(c(), target_c())
qibo.set_backend(original_backend)
def _initialize_circuit(self):
"""Creates variational circuit."""
C = Circuit(1)
for l in range(self.layers):
C.add(gates.RY(0, theta=0))
C.add(gates.RZ(0, theta=0))
return C
def test_qgan_circuit_error():
if not K.check_availability("tensorflow"): # pragma: no cover
pytest.skip("Skipping StyleQGAN test because tensorflow backend is not available.")
original_backend = qibo.get_backend()
qibo.set_backend("tensorflow")
reference_distribution = generate_distribution(10)
# use wrong number of qubits so that we capture the error
nqubits = reference_distribution.shape[1] + 1
nlayers = 1
circuit = models.Circuit(nqubits)
for l in range(nlayers):
for q in range(nqubits):
circuit.add(gates.RY(q, 0))
circuit.add(gates.RZ(q, 0))
for i in range(0, nqubits - 1):
circuit.add(gates.CZ(i, i + 1))
circuit.add(gates.CZ(nqubits - 1, 0))
for q in range(nqubits):
circuit.add(gates.RY(q, 0))
initial_params = np.random.uniform(-0.15, 0.15, 18)
qgan = models.StyleQGAN(
latent_dim=2,
circuit=circuit,
set_parameters=lambda x: x
)
with pytest.raises(ValueError):
qgan.fit(reference_distribution, initial_params=initial_params, n_epochs=1, save=False)
qibo.set_backend(original_backend)
def test_variable_backpropagation(backend):
if backend == "custom":
pytest.skip("Custom gates do not support automatic differentiation.")
original_backend = qibo.get_backend()
qibo.set_backend(backend)
if K.name != "tensorflow":
qibo.set_backend(original_backend)
pytest.skip("Backpropagation is not supported by {}.".format(K.name))
theta = K.optimization.Variable(0.1234, dtype=K.dtypes('DTYPE'))
# TODO: Fix parametrized gates so that `Circuit` can be defined outside
# of the gradient tape
with K.optimization.GradientTape() as tape:
c = Circuit(1)
c.add(gates.X(0))
c.add(gates.RZ(0, theta))
loss = K.real(c()[-1])
grad = tape.gradient(loss, theta)
target_loss = np.cos(theta / 2.0)
np.testing.assert_allclose(loss, target_loss)
target_grad = -np.sin(theta / 2.0) / 2.0
np.testing.assert_allclose(grad, target_grad)
qibo.set_backend(original_backend)
def test_cu1_cirq():
c1 = Circuit(2)
c1.add(gates.RX(0, 0.1234))
c1.add(gates.RZ(1, 0.4321))
c1.add(gates.CU1(0, 1, 0.567))
# catches unknown gate "cu1"
with pytest.raises(exception.QasmException):
c2 = circuit_from_qasm(c1.to_qasm())
def test_crotations_cirq():
c1 = Circuit(3)
c1.add(gates.RX(0, 0.1))
c1.add(gates.RZ(1, 0.4))
c1.add(gates.CRX(0, 2, 0.5))
c1.add(gates.RY(1, 0.3).controlled_by(2))
# catches unknown gate "crx"
with pytest.raises(exception.QasmException):
c2 = circuit_from_qasm(c1.to_qasm())
def test_circuit_on_qubits_controlled_by_execution(backend, accelerators):
smallc = Circuit(3)
smallc.add(gates.RX(0, theta=0.1).controlled_by(1, 2))
smallc.add(gates.RY(1, theta=0.2).controlled_by(0))
smallc.add(gates.RX(2, theta=0.3).controlled_by(1, 0))
smallc.add(gates.RZ(1, theta=0.4).controlled_by(0, 2))
largec = Circuit(6, accelerators=accelerators)
largec.add(gates.H(i) for i in range(6))
largec.add(smallc.on_qubits(1, 4, 3))
targetc = Circuit(6)
targetc.add(gates.H(i) for i in range(6))
targetc.add(gates.RX(1, theta=0.1).controlled_by(3, 4))
targetc.add(gates.RY(4, theta=0.2).controlled_by(1))
targetc.add(gates.RX(3, theta=0.3).controlled_by(1, 4))
targetc.add(gates.RZ(4, theta=0.4).controlled_by(1, 3))
assert largec.depth == targetc.depth
K.assert_allclose(largec(), targetc())
def test_rz(backend, applyx):
theta = 0.1234
if applyx:
gatelist = [gates.X(0)]
else:
gatelist = []
gatelist.append(gates.RZ(0, theta))
final_state = apply_gates(gatelist, nqubits=1)
target_state = np.zeros_like(final_state)
p = int(applyx)
target_state[p] = np.exp((2 * p - 1) * 1j * theta / 2.0)
K.assert_allclose(final_state, target_state)
def ansatz(p=0):
"""Ansatz for driving a random state into its up-tp-phases canonical form.
Args:
p (float): probability of occuring a single-qubit depolarizing error
Returns:
Qibo circuit implementing the variational ansatz.
"""
C = Circuit(3)
for i in range(3):
C.add(gates.RZ(i, theta=0))
C.add(gates.RY(i, theta=0))
C.add(gates.RZ(i, theta=0))
if p > 0:
C.add(gates.NoiseChannel(i, px=p / 3, py=p / 3, pz=p / 3))
for i in range(3):
if p > 0:
C.add(gates.NoiseChannel(i, px=10 * p))
C.add(gates.M(i))
return C
def test_construct_unitary(backend):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
target_matrix = np.array([[1, 1], [1, -1]]) / np.sqrt(2)
np.testing.assert_allclose(gates.H(0).unitary, target_matrix)
target_matrix = np.array([[0, 1], [1, 0]])
np.testing.assert_allclose(gates.X(0).unitary, target_matrix)
target_matrix = np.array([[0, -1j], [1j, 0]])
np.testing.assert_allclose(gates.Y(0).unitary, target_matrix)
target_matrix = np.array([[1, 0], [0, -1]])
np.testing.assert_allclose(gates.Z(1).unitary, target_matrix)
target_matrix = np.array([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 0, 1],
[0, 0, 1, 0]])
np.testing.assert_allclose(gates.CNOT(0, 1).unitary, target_matrix)
target_matrix = np.diag([1, 1, 1, -1])
np.testing.assert_allclose(gates.CZ(1, 3).unitary, target_matrix)
target_matrix = np.array([[1, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 0],
[0, 0, 0, 1]])
np.testing.assert_allclose(gates.SWAP(2, 4).unitary, target_matrix)
target_matrix = np.array([[1, 0, 0, 0, 0, 0, 0,
0], [0, 1, 0, 0, 0, 0, 0, 0],
[0, 0, 1, 0, 0, 0, 0,
0], [0, 0, 0, 1, 0, 0, 0, 0],
[0, 0, 0, 0, 1, 0, 0,
0], [0, 0, 0, 0, 0, 1, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 1],
[0, 0, 0, 0, 0, 0, 1, 0]])
np.testing.assert_allclose(gates.TOFFOLI(1, 2, 3).unitary, target_matrix)
theta = 0.1234
target_matrix = np.array([[np.cos(theta / 2.0), -1j * np.sin(theta / 2.0)],
[-1j * np.sin(theta / 2.0),
np.cos(theta / 2.0)]])
np.testing.assert_allclose(gates.RX(0, theta).unitary, target_matrix)
target_matrix = np.array([[np.cos(theta / 2.0), -np.sin(theta / 2.0)],
[np.sin(theta / 2.0),
np.cos(theta / 2.0)]])
np.testing.assert_allclose(gates.RY(0, theta).unitary, target_matrix)
target_matrix = np.diag(
[np.exp(-1j * theta / 2.0),
np.exp(1j * theta / 2.0)])
np.testing.assert_allclose(gates.RZ(0, theta).unitary, target_matrix)
target_matrix = np.diag([1, np.exp(1j * theta)])
np.testing.assert_allclose(gates.U1(0, theta).unitary, target_matrix)
target_matrix = np.diag([1, 1, 1, np.exp(1j * theta)])
np.testing.assert_allclose(gates.CU1(0, 1, theta).unitary, target_matrix)
from qibo import matrices
target_matrix = np.array([[1, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 0],
[0, 0, 0, 1]])
np.testing.assert_allclose(matrices.SWAP, target_matrix)
qibo.set_backend(original_backend)
def test_czpow():
c = Circuit(2)
c.add(gates.RX(0, 0.1234))
c.add(gates.RZ(1, 0.4321))
c.add(gates.CZPow(0, 1, 0.567))
target = f"""// Generated by QIBO {__version__}
OPENQASM 2.0;
include "qelib1.inc";
qreg q[2];
rx(0.1234) q[0];
rz(0.4321) q[1];
crz(0.567) q[0],q[1];"""
assert_strings_equal(c.to_qasm(), target)
def test_custom_qgan():
if not K.check_availability("tensorflow"): # pragma: no cover
pytest.skip("Skipping StyleQGAN test because tensorflow backend is not available.")
original_backend = qibo.get_backend()
qibo.set_backend("tensorflow")
def set_params(circuit, params, x_input, i):
"""Set the parameters for the quantum generator circuit."""
p = []
index = 0
noise = 0
for l in range(1):
for q in range(3):
p.append(params[index]*x_input[noise][i] + params[index+1])
index+=2
noise=(noise+1)%2
p.append(params[index]*x_input[noise][i] + params[index+1])
index+=2
noise=(noise+1)%2
for q in range(3):
p.append(params[index]*x_input[noise][i] + params[index+1])
index+=2
noise=(noise+1)%2
circuit.set_parameters(p)
nqubits = 3
nlayers = 1
reference_distribution = generate_distribution(10)
circuit = models.Circuit(nqubits)
for l in range(nlayers):
for q in range(nqubits):
circuit.add(gates.RY(q, 0))
circuit.add(gates.RZ(q, 0))
for i in range(0, nqubits - 1):
circuit.add(gates.CZ(i, i + 1))
circuit.add(gates.CZ(nqubits - 1, 0))
for q in range(nqubits):
circuit.add(gates.RY(q, 0))
initial_params = np.random.uniform(-0.15, 0.15, 18)
qgan = models.StyleQGAN(
latent_dim=2,
circuit=circuit,
set_parameters=set_params
)
qgan.fit(reference_distribution, initial_params=initial_params, n_epochs=1, save=False)
assert qgan.latent_dim == 2
assert qgan.batch_samples == 128
assert qgan.n_epochs == 1
assert qgan.lr == 0.5
qibo.set_backend(original_backend)
def test_rz_phase0(backend):
"""Check RZ gate is working properly when qubit is on |0>."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = 0.1234
c = Circuit(2)
c.add(gates.RZ(0, theta))
final_state = c.execute().numpy()
target_state = np.zeros_like(final_state)
target_state[0] = np.exp(-1j * theta / 2.0)
np.testing.assert_allclose(final_state, target_state)
qibo.set_backend(original_backend)
def test_from_qasm_parametrized_gates():
import numpy as np
target = """OPENQASM 2.0;
qreg q[2];
rx(0.1234) q[0];
rz(0.4321) q[1];
cu1(0.567) q[0],q[1];"""
c = Circuit.from_qasm(target)
assert c.depth == 2
assert isinstance(c.queue[0], gates.RX)
assert isinstance(c.queue[1], gates.RZ)
assert isinstance(c.queue[2], gates.CU1)
c2 = Circuit(2)
c2.add([gates.RX(0, 0.1234), gates.RZ(1, 0.4321), gates.CU1(0, 1, 0.567)])
np.testing.assert_allclose(c2().numpy(), c().numpy())
def test_variable_backpropagation(backend):
if not K.supports_gradients:
pytest.skip("Backpropagation is not supported by {}.".format(K.name))
theta = K.optimization.Variable(0.1234, dtype=K.dtypes('DTYPE'))
# TODO: Fix parametrized gates so that `Circuit` can be defined outside
# of the gradient tape
with K.optimization.GradientTape() as tape:
c = Circuit(1)
c.add(gates.X(0))
c.add(gates.RZ(0, theta))
loss = K.real(c()[-1])
grad = tape.gradient(loss, theta)
target_loss = np.cos(theta / 2.0)
K.assert_allclose(loss, target_loss)
target_grad = -np.sin(theta / 2.0) / 2.0
K.assert_allclose(grad, target_grad)
def test_crotations():
c = Circuit(3)
c.add(gates.RX(0, 0.1))
c.add(gates.RZ(1, 0.4))
c.add(gates.CRX(0, 2, 0.5))
c.add(gates.RY(1, 0.3).controlled_by(2))
target = f"""// Generated by QIBO {__version__}
OPENQASM 2.0;
include "qelib1.inc";
qreg q[3];
rx(0.1) q[0];
rz(0.4) q[1];
crx(0.5) q[0],q[2];
cry(0.3) q[2],q[1];"""
assert_strings_equal(c.to_qasm(), target)
c = Circuit(2)
c.add(gates.CU2(0, 1, 0.1, 0.2))
with pytest.raises(ValueError):
target = c.to_qasm()
def test_ugates():
c = Circuit(3)
c.add(gates.RX(0, 0.1))
c.add(gates.RZ(1, 0.4))
c.add(gates.U2(2, 0.5, 0.6))
c.add(gates.CU1(0, 1, 0.7))
c.add(gates.CU3(2, 1, 0.2, 0.3, 0.4))
target = f"""// Generated by QIBO {__version__}
OPENQASM 2.0;
include "qelib1.inc";
qreg q[3];
rx(0.1) q[0];
rz(0.4) q[1];
u2(0.5, 0.6) q[2];
cu1(0.7) q[0],q[1];
cu3(0.2, 0.3, 0.4) q[2],q[1];"""
assert_strings_equal(c.to_qasm(), target)
c = Circuit(2)
c.add(gates.CU2(0, 1, 0.1, 0.2))
with pytest.raises(ValueError):
target = c.to_qasm()
def test_variable_backpropagation(backend):
"""Check that backpropagation works when using `tf.Variable` parameters."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
import tensorflow as tf
from qibo.config import DTYPES
theta = tf.Variable(0.1234, dtype=DTYPES.get('DTYPE'))
# TODO: Fix parametrized gates so that `Circuit` can be defined outside
# of the gradient tape
with tf.GradientTape() as tape:
c = Circuit(1)
c.add(gates.X(0))
c.add(gates.RZ(0, theta))
loss = tf.math.real(c()[-1])
grad = tape.gradient(loss, theta)
target_loss = np.cos(theta.numpy() / 2.0)
np.testing.assert_allclose(loss.numpy(), target_loss)
target_grad = -np.sin(theta.numpy() / 2.0) / 2.0
np.testing.assert_allclose(grad.numpy(), target_grad)
qibo.set_backend(original_backend)
def ansatz_Weighted_2D(layers, qubits=1):
"""
3 parameters per layer: Ry(wx + a), Rz(b)
"""
circuit = models.Circuit(qubits)
circuit.add(gates.H(0))
for _ in range(layers):
circuit.add(gates.RZ(0, theta=0))
circuit.add(gates.RY(0, theta=0))
def rotation(theta, x):
p = circuit.get_parameters()
i = 0
j = 0
for l in range(layers):
p[i] = theta[j] + theta[j + 1:j + 3] @ x
p[i + 1] = theta[j + 3]
i += 2
j += 4
return p
nparams = 4 * layers
return circuit, rotation, nparams
def ansatz_Weighted(layers, qubits=1):
"""Fourier Ansatz implementation. 4 parameters per layer and
qubit: Ry(wx + a), Rz(v log(x) + b)
Args:
layers (int): number of layers.
qubits (int): number of qubits.
Returns:
The circuit, the rotation function and the total number of
parameters.
"""
circuit = models.Circuit(qubits)
for _ in range(layers - 1):
for q in range(qubits):
circuit.add(gates.RY(q, theta=0))
circuit.add(gates.RZ(q, theta=0))
if qubits > 1:
for q in range(0, qubits, 2):
circuit.add(gates.CZPow(q, (q + 1) % qubits, theta=0))
if qubits > 2:
for q in range(1, qubits + 1, 2):
circuit.add(gates.CZPow(q, (q + 1) % qubits, theta=0))
for q in range(qubits):
circuit.add(gates.RY(q, theta=0))
circuit.add(gates.RZ(q, theta=0))
def rotation(theta, x):
p = circuit.get_parameters()
i = 0
j = 0
for l in range(layers - 1):
for q in range(qubits):
p[i] = theta[j] + theta[j + 1] * map_to(x)
p[i + 1] = theta[j + 2] + theta[j + 3] * maplog_to(x)
i += 2
j += 4
if qubits > 1:
for q in range(0, qubits, 2):
p[i] = theta[j]
i += 1
j += 1
if qubits > 2:
for q in range(1, qubits + 1, 2):
p[i] = theta[j]
i += 1
j += 1
for q in range(qubits):
p[i] = theta[j] + theta[j + 1] * map_to(x)
p[i + 1] = theta[j + 2] + theta[j + 3] * maplog_to(x)
i += 2
j += 4
return p
nparams = 4 * layers * qubits + \
(layers - 1) * int(np.ceil(qubits / 2)) * \
(int(qubits > 1) + int(qubits > 2))
return circuit, rotation, nparams
def ansatz_Fourier(layers, qubits=1):
"""Fourier Ansatz implementation. It is composed by 3 parameters per layer
and qubit: U3(a, b, c) Ry(x) || U3(a, b, c) Ry(log x).
Args:
layers (int): number of layers.
qubits (int): number of qubits.
Returns:
The circuit, the rotation function and the total number of parameters.
"""
circuit = models.Circuit(qubits)
for l in range(layers - 1):
for q in range(qubits):
for _ in range(2):
circuit.add(gates.RY(q, theta=0))
circuit.add(gates.RZ(q, theta=0))
circuit.add(gates.RY(q, theta=0))
if qubits > 1:
for q in range(0, qubits, 2):
circuit.add(gates.CZPow(q, q + 1, theta=0))
if qubits > 2:
for q in range(1, qubits + 1, 2):
circuit.add(gates.CZPow(q, (q + 1) % qubits, theta=0))
for q in range(qubits):
for _ in range(2):
circuit.add(gates.RY(q, theta=0))
circuit.add(gates.RZ(q, theta=0))
circuit.add(gates.RY(q, theta=0))
def rotation(theta, x):
p = circuit.get_parameters()
i = 0
j = 0
for l in range(layers - 1):
for q in range(qubits):
p[i] = map_to(x)
p[i + 1:i + 3] = theta[j:j + 2]
i += 3
j += 2
p[i] = .5 * maplog_to(x)
p[i + 1:i + 3] = theta[j:j + 2]
i += 3
j += 2
if qubits > 1:
for q in range(0, qubits, 2):
p[i] = theta[j]
i += 1
j += 1
if qubits > 2:
for q in range(1, qubits + 1, 2):
p[i] = theta[j]
i += 1
j += 1
for q in range(qubits):
p[i] = .5 * map_to(x)
p[i + 1:i + 3] = theta[j:j + 2]
i += 3
j += 2
p[i] = .5 * maplog_to(x)
p[i + 1:i + 3] = theta[j:j + 2]
i += 3
j += 2
return p
nparams = 4 * layers * qubits + \
(layers - 1) * int(np.ceil(qubits / 2)) * \
(int(qubits > 1) + int(qubits > 2))
return circuit, rotation, nparams
def last_rotation(circuit, nqubits):
for k in range(nqubits):
circuit.add(gates.RZ(k, np.random.rand()))
circuit.add(gates.RX(k, np.random.rand()))
def rotations():
for q in range(self.nqubits):
yield gates.RX(q, theta=0)
yield gates.RZ(q, theta=0)
yield gates.RX(q, theta=0)
def fit(self,
reference,
initial_params=None,
batch_samples=128,
n_epochs=20000,
lr=0.5,
save=True):
"""Execute qGAN training.
Args:
reference (array): samples from the reference input distribution.
initial_parameters (array): initial parameters for the quantum generator. If not provided,
the default initial parameters will be used.
discriminator (:class:`tensorflow.keras.models`): custom classical discriminator. If not provided,
the default classical discriminator will be used.
batch_samples (int): number of training examples utilized in one iteration.
n_epochs (int): number of training iterations.
lr (float): initial learning rate for the quantum generator.
It controls how much to change the model each time the weights are updated.
save (bool): If ``True`` the results of training (trained parameters and losses)
will be saved on disk. Default is ``True``.
"""
if initial_params is None and self.circuit is not None:
raise_error(
ValueError,
"Set the initial parameters for your custom quantum generator."
)
elif initial_params is not None and self.circuit is None:
raise_error(
ValueError,
"Define the custom quantum generator to use custom initial parameters."
)
self.reference = reference
self.nqubits = reference.shape[1]
self.training_samples = reference.shape[0]
self.initial_params = initial_params
self.batch_samples = batch_samples
self.n_epochs = n_epochs
self.lr = lr
# create classical discriminator
if self.discriminator is None:
discriminator = self.define_discriminator()
else:
discriminator = self.discriminator
if discriminator.input_shape[1] is not self.nqubits:
raise_error(
ValueError,
"The number of input neurons in the discriminator has to be equal to "
"the number of qubits in the circuit (dimension of the input reference distribution)."
)
# create quantum generator
if self.circuit is None:
circuit = models.Circuit(self.nqubits)
for l in range(self.layers):
for q in range(self.nqubits):
circuit.add(gates.RY(q, 0))
circuit.add(gates.RZ(q, 0))
circuit.add(gates.RY(q, 0))
circuit.add(gates.RZ(q, 0))
for i in range(0, self.nqubits - 1):
circuit.add(gates.CRY(i, i + 1, 0))
circuit.add(gates.CRY(self.nqubits - 1, 0, 0))
for q in range(self.nqubits):
circuit.add(gates.RY(q, 0))
else:
circuit = self.circuit
if circuit.nqubits != self.nqubits:
raise_error(
ValueError,
"The number of qubits in the circuit has to be equal to "
"the number of dimensions in the reference distribution.")
# define hamiltonian to generate fake samples
def hamiltonian(nqubits, position):
identity = [[1, 0], [0, 1]]
m0 = hamiltonians.Z(1).matrix
kron = []
for i in range(nqubits):
if i == position:
kron.append(m0)
else:
kron.append(identity)
for i in range(nqubits - 1):
if i == 0:
ham = np.kron(kron[i + 1], kron[i])
else:
ham = np.kron(kron[i + 1], ham)
ham = hamiltonians.Hamiltonian(nqubits, ham)
return ham
hamiltonians_list = []
for i in range(self.nqubits):
hamiltonians_list.append(hamiltonian(self.nqubits, i))
# train model
self.train(discriminator, circuit, hamiltonians_list, save)