def test_circuit_on_qubits_with_varlayer_execution(backend, accelerators):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
thetas = np.random.random([2, 4])
smallc = Circuit(4)
smallc.add(gates.VariationalLayer(range(4), [(0, 1), (2, 3)],
gates.RX, gates.CNOT,
thetas[0]))
largec = Circuit(8, accelerators=accelerators)
largec.add(smallc.on_qubits(*range(0, 8, 2)))
largec.add(gates.VariationalLayer(range(1, 8, 2), [(1, 3), (5, 7)],
gates.RY, gates.CZ,
thetas[1]))
targetc = Circuit(8)
targetc.add(gates.VariationalLayer(range(0, 8, 2), [(0, 2), (4, 6)],
gates.RX, gates.CNOT,
thetas[0]))
targetc.add(gates.VariationalLayer(range(1, 8, 2), [(1, 3), (5, 7)],
gates.RY, gates.CZ,
thetas[1]))
assert largec.depth == targetc.depth
np.testing.assert_allclose(largec(), targetc())
qibo.set_backend(original_backend)
def test_set_parameters_with_variationallayer(backend, accelerators, nqubits):
"""Check updating parameters of variational layer."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = np.random.random(nqubits)
c = Circuit(nqubits, accelerators)
pairs = [(i, i + 1) for i in range(0, nqubits - 1, 2)]
c.add(
gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta))
target_c = Circuit(nqubits)
target_c.add((gates.RY(i, theta[i]) for i in range(nqubits)))
target_c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
np.testing.assert_allclose(c(), target_c())
# Test setting VariationalLayer using a list
new_theta = np.random.random(nqubits)
c.set_parameters([np.copy(new_theta)])
target_c.set_parameters(np.copy(new_theta))
np.testing.assert_allclose(c(), target_c())
# Test setting VariationalLayer using an array
new_theta = np.random.random(nqubits)
c.set_parameters(np.copy(new_theta))
target_c.set_parameters(np.copy(new_theta))
np.testing.assert_allclose(c(), target_c())
qibo.set_backend(original_backend)
def test_set_parameters_with_double_variationallayer(backend, accelerators,
nqubits, trainable):
"""Check updating parameters of variational layer."""
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = np.random.random((3, nqubits))
c = Circuit(nqubits, accelerators)
pairs = [(i, i + 1) for i in range(0, nqubits - 1, 2)]
c.add(
gates.VariationalLayer(range(nqubits),
pairs,
gates.RY,
gates.CZ,
theta[0],
theta[1],
trainable=trainable))
c.add((gates.RX(i, theta[2, i]) for i in range(nqubits)))
target_c = Circuit(nqubits)
target_c.add((gates.RY(i, theta[0, i]) for i in range(nqubits)))
target_c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
target_c.add((gates.RY(i, theta[1, i]) for i in range(nqubits)))
target_c.add((gates.RX(i, theta[2, i]) for i in range(nqubits)))
np.testing.assert_allclose(c(), target_c())
new_theta = np.random.random(3 * nqubits)
if trainable:
c.set_parameters(np.copy(new_theta))
else:
c.set_parameters(np.copy(new_theta[2 * nqubits:]))
new_theta[:2 * nqubits] = theta[:2].ravel()
target_c.set_parameters(np.copy(new_theta))
np.testing.assert_allclose(c(), target_c())
qibo.set_backend(original_backend)
def test_variational_layer_density_matrix(backend, nqubits):
from qibo.models import Circuit
theta = 2 * np.pi * np.random.random(nqubits)
c = Circuit(nqubits, density_matrix=True)
c.add((gates.RY(i, t) for i, t in enumerate(theta)))
c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
target_state = c()
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
c = Circuit(nqubits, density_matrix=True)
c.add(gates.VariationalLayer(range(nqubits), pairs,
gates.RY, gates.CZ, theta))
final_state = c()
K.assert_allclose(target_state, final_state)
gate = gates.VariationalLayer(range(nqubits), pairs,
gates.RY, gates.CZ, theta)
gate.density_matrix = True
final_state = gate(c.get_initial_state())
K.assert_allclose(target_state, final_state)
def test_variational_layer_construct_unitary(backend):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
pairs = list((i, i + 1) for i in range(0, 5, 2))
theta = 2 * np.pi * np.random.random(6)
gate = gates.VariationalLayer(range(6), pairs, gates.RY, gates.CZ, theta)
with pytest.raises(ValueError):
gate.construct_unitary()
qibo.set_backend(original_backend)
def test_circuit_add_layer(backend, nqubits, accelerators):
c = Circuit(nqubits, accelerators)
qubits = list(range(nqubits))
pairs = [(2 * i, 2 * i + 1) for i in range(nqubits // 2)]
params = nqubits * [0.1]
c.add(gates.VariationalLayer(qubits, pairs, gates.RY, gates.CZ, params))
assert len(c.queue) == nqubits // 2 + nqubits % 2
for gate in c.queue:
assert isinstance(gate, gates.Unitary)
def test_variational_layer_dagger(backend, nqubits):
theta = 2 * np.pi * np.random.random((2, nqubits))
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
gate = gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta[0], theta[1])
c = Circuit(nqubits)
c.add((gate, gate.dagger()))
initial_state = random_state(nqubits)
final_state = c(np.copy(initial_state))
K.assert_allclose(final_state, initial_state)
def test_construct_unitary_errors(backend):
qibo.set_backend(backend)
gate = gates.M(0)
with pytest.raises(ValueError):
matrix = gate.unitary
pairs = list((i, i + 1) for i in range(0, 5, 2))
theta = 2 * np.pi * np.random.random(6)
gate = gates.VariationalLayer(range(6), pairs, gates.RY, gates.CZ, theta)
with pytest.raises(ValueError):
matrix = gate.unitary
def test_variational_layer(backend, nqubits):
theta = 2 * np.pi * np.random.random(nqubits)
gatelist = [gates.RY(i, t) for i, t in enumerate(theta)]
gatelist.extend(gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2))
target_state = apply_gates(gatelist, nqubits=nqubits)
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
gate = gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta)
final_state = apply_gates([gate], nqubits=nqubits)
K.assert_allclose(target_state, final_state)
def test_variational_layer(backend, nqubits):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = 2 * np.pi * np.random.random(nqubits)
c = models.Circuit(nqubits, density_matrix=True)
c.add((gates.RY(i, t) for i, t in enumerate(theta)))
c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
target_state = c()
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
c = models.Circuit(nqubits, density_matrix=True)
c.add(
gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta))
final_state = c()
np.testing.assert_allclose(target_state, final_state)
gate = gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta)
gate.density_matrix = True
final_state = gate(c.get_initial_state())
np.testing.assert_allclose(target_state, final_state)
qibo.set_backend(original_backend)
def varlayer_circuit(nqubits, nlayers):
"""Creates variational circuit using ``VariationalLayer`` gate."""
circuit = models.Circuit(nqubits)
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
theta = np.zeros(nqubits)
for l in range(nlayers):
circuit.add(
gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta, theta))
circuit.add((gates.CZ(i, i + 1) for i in range(1, nqubits - 2, 2)))
circuit.add(gates.CZ(0, nqubits - 1))
circuit.add((gates.RY(i, theta) for i in range(nqubits)))
return circuit
def test_variational_layer_errors(backend):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
c = Circuit(6)
pairs = list((i, i + 1) for i in range(0, 5, 2))
with pytest.raises(ValueError):
c.add(gates.VariationalLayer(range(6), pairs,
gates.RY, gates.CZ,
np.zeros(6), np.zeros(7)))
with pytest.raises(ValueError):
c.add(gates.VariationalLayer(range(7), pairs,
gates.RY, gates.CZ,
np.zeros(7), np.zeros(7)))
with pytest.raises(ValueError):
c.add(gates.VariationalLayer(range(10), pairs,
gates.RY, gates.CZ,
np.zeros(10), np.zeros(10)))
gate = gates.VariationalLayer(range(6), pairs, gates.RY, gates.CZ,
np.zeros(6), np.zeros(6))
np.testing.assert_allclose(gate.parameter, np.zeros(12))
qibo.set_backend(original_backend)
def test_variational_two_layers(backend, accelerators, nqubits):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = 2 * np.pi * np.random.random(2 * nqubits)
theta_iter = iter(theta)
c = Circuit(nqubits)
c.add((gates.RY(i, next(theta_iter)) for i in range(nqubits)))
c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
c.add((gates.RY(i, next(theta_iter)) for i in range(nqubits)))
c.add((gates.CZ(i, i + 1) for i in range(1, nqubits - 2, 2)))
c.add(gates.CZ(0, nqubits - 1))
target_state = c().numpy()
c = Circuit(nqubits, accelerators)
theta = theta.reshape((2, nqubits))
pairs1 = list((i, i + 1) for i in range(0, nqubits - 1, 2))
pairs2 = list((i, i + 1) for i in range(1, nqubits - 2, 2))
pairs2.append((0, nqubits - 1))
c.add(
gates.VariationalLayer(range(nqubits), pairs1, gates.RY, gates.CZ,
theta[0]))
c.add(
gates.VariationalLayer(range(nqubits), pairs2, gates.RY, gates.CZ,
theta[1]))
final_state = c().numpy()
np.testing.assert_allclose(target_state, final_state)
c = Circuit(nqubits, accelerators)
theta = theta.reshape((2, nqubits))
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
c.add(
gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta[0], theta[1]))
c.add((gates.CZ(i, i + 1) for i in range(1, nqubits - 2, 2)))
c.add(gates.CZ(0, nqubits - 1))
final_state = c().numpy()
np.testing.assert_allclose(target_state, final_state)
qibo.set_backend(original_backend)
def OptimizedVariationalCircuit(nqubits, nlayers=1, theta_values=None):
if theta_values is None:
theta = 2 * np.pi * np.random.random((2 * nlayers, nqubits))
else:
theta = theta_values.reshape((2 * nlayers, nqubits))
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
for l in range(nlayers):
yield gates.VariationalLayer(range(nqubits), pairs,
gates.RY, gates.CZ,
theta[2 * l], theta[2 * l + 1])
for i in range(1, nqubits - 2, 2):
yield gates.CZ(i, i + 1)
yield gates.CZ(0, nqubits - 1)
def test_variational_layer_dagger(backend, nqubits):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = 2 * np.pi * np.random.random((2, nqubits))
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
gate = gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta[0], theta[1])
c = Circuit(nqubits)
c.add((gate, gate.dagger()))
initial_state = utils.random_numpy_state(nqubits)
final_state = c(np.copy(initial_state)).numpy()
np.testing.assert_allclose(final_state, initial_state)
qibo.set_backend(original_backend)
def test_variational_layer_call(nqubits):
original_backend = qibo.get_backend()
qibo.set_backend("custom")
theta = 2 * np.pi * np.random.random(nqubits)
c = Circuit(nqubits)
c.add((gates.RY(i, t) for i, t in enumerate(theta)))
c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
target_state = c().numpy()
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
gate = gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
theta)
final_state = gate(c._default_initial_state()).numpy()
np.testing.assert_allclose(target_state, final_state)
qibo.set_backend(original_backend)
def test_circuit_add_layer(backend, nqubits, accelerators):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
c = Circuit(nqubits, accelerators)
qubits = list(range(nqubits))
pairs = [(2 * i, 2 * i + 1) for i in range(nqubits // 2)]
params = nqubits * [0.1]
c.add(gates.VariationalLayer(qubits, pairs, gates.RY, gates.CZ, params))
assert len(c.queue) == nqubits // 2 + nqubits % 2
if backend == "custom":
target_gate_cls = gates.Unitary
else:
from qibo.core.gates import Unitary as target_gate_cls
for gate in c.queue:
assert isinstance(gate, target_gate_cls)
qibo.set_backend(original_backend)
def test_variational_one_layer(backend, accelerators, nqubits):
original_backend = qibo.get_backend()
qibo.set_backend(backend)
theta = 2 * np.pi * np.random.random(nqubits)
c = Circuit(nqubits)
c.add((gates.RY(i, t) for i, t in enumerate(theta)))
c.add((gates.CZ(i, i + 1) for i in range(0, nqubits - 1, 2)))
target_state = c().numpy()
c = Circuit(nqubits, accelerators)
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
c.add(gates.VariationalLayer(range(nqubits), pairs,
gates.RY, gates.CZ,
theta))
final_state = c().numpy()
np.testing.assert_allclose(target_state, final_state)
qibo.set_backend(original_backend)
def AAVQE(nqubits, layers, maxsteps, T_max, initial_parameters,
easy_hamiltonian, problem_hamiltonian):
"""Implements the Adiabatically Assisted Variational Quantum Eigensolver (AAVQE).
Args:
nqubits (int): number of quantum bits.
layers (int): number of ansatz layers.
maxsteps (int): number of maximum iterations on each adiabatic step.
T_max (int): number of maximum adiabatic steps.
initial_parameters (array or list): values of the initial parameters.
easy_hamiltonian (qibo.hamiltonians.Hamiltonian): initial Hamiltonian object.
problem_hamiltonian (qibo.hamiltonians.Hamiltonian): problem Hamiltonian object.
Returns:
Groundstate energy of the problem Hamiltonian and best set of parameters.
"""
# Create variational circuit
pairs = list((i, i + 1) for i in range(0, nqubits - 1, 2))
circuit = models.Circuit(nqubits)
for l in range(layers):
circuit.add(
gates.VariationalLayer(range(nqubits), pairs, gates.RY, gates.CZ,
np.zeros(nqubits), np.zeros(nqubits)))
circuit.add((gates.CZ(i, i + 1) for i in range(1, nqubits - 2, 2)))
circuit.add(gates.CZ(0, nqubits - 1))
circuit.add((gates.RY(i, theta=0) for i in range(nqubits)))
for t in range(T_max + 1):
s = t / T_max
print('s =', s)
hamiltonian = (1 - s) * easy_hamiltonian + s * problem_hamiltonian
vqe = models.VQE(circuit, hamiltonian)
energy, params = vqe.minimize(initial_parameters,
method='Nelder-Mead',
options={'maxfev': maxsteps},
compile=False)
initial_parameters = params
return energy, params