def test_ground_state_particle_nonconserving(self):
"""Test getting the ground state preparation circuit for a Hamiltonian
that does not conserve particle number."""
for n_qubits in self.n_qubits_range:
# Initialize a particle-number-conserving Hamiltonian
quadratic_hamiltonian = random_quadratic_hamiltonian(
n_qubits, False, True)
# Compute the true ground state
sparse_operator = get_sparse_operator(quadratic_hamiltonian)
ground_energy, _ = get_ground_state(sparse_operator)
# Obtain the circuit
circuit_description, start_orbitals = (
gaussian_state_preparation_circuit(quadratic_hamiltonian))
# Initialize the starting state
state = jw_configuration_state(start_orbitals, n_qubits)
# Apply the circuit
particle_hole_transformation = (
jw_sparse_particle_hole_transformation_last_mode(n_qubits))
for parallel_ops in circuit_description:
for op in parallel_ops:
if op == 'pht':
state = particle_hole_transformation.dot(state)
else:
i, j, theta, phi = op
state = jw_sparse_givens_rotation(
i, j, theta, phi, n_qubits).dot(state)
# Check that the state obtained using the circuit is a ground state
difference = sparse_operator * state - ground_energy * state
discrepancy = numpy.amax(numpy.abs(difference))
self.assertAlmostEqual(discrepancy, 0)
def test_bad_input(self):
"""Test bad input."""
with self.assertRaises(ValueError):
description, n_electrons = gaussian_state_preparation_circuit('a')