def test_simulate_trotter_bad_hamiltonian_type_raises_error():
qubits = cirq.LineQubit.range(2)
hamiltonian = openfermion.FermionOperator()
time = 1.0
with pytest.raises(TypeError):
_ = next(simulate_trotter(qubits, hamiltonian, time, algorithm=None))
with pytest.raises(TypeError):
_ = next(
simulate_trotter(qubits,
hamiltonian,
time,
algorithm=LINEAR_SWAP_NETWORK))
def test_simulate_trotter_unsupported_trotter_step_raises_error():
qubits = cirq.LineQubit.range(2)
control = cirq.LineQubit(-1)
hamiltonian = openfermion.random_diagonal_coulomb_hamiltonian(2, seed=0)
time = 1.0
class EmptyTrotterAlgorithm(TrotterAlgorithm):
supported_types = {openfermion.DiagonalCoulombHamiltonian}
algorithm = EmptyTrotterAlgorithm()
with pytest.raises(ValueError):
_ = next(
simulate_trotter(qubits,
hamiltonian,
time,
order=0,
algorithm=algorithm))
with pytest.raises(ValueError):
_ = next(
simulate_trotter(qubits,
hamiltonian,
time,
order=1,
algorithm=algorithm))
with pytest.raises(ValueError):
_ = next(
simulate_trotter(qubits,
hamiltonian,
time,
order=0,
algorithm=algorithm,
control_qubit=control))
with pytest.raises(ValueError):
_ = next(
simulate_trotter(qubits,
hamiltonian,
time,
order=1,
algorithm=algorithm,
control_qubit=control))
def test_simulate_trotter_simulate(hamiltonian, time, initial_state,
exact_state, order, n_steps, algorithm,
result_fidelity):
n_qubits = openfermion.count_qubits(hamiltonian)
qubits = cirq.LineQubit.range(n_qubits)
start_state = initial_state
circuit = cirq.Circuit(
simulate_trotter(qubits, hamiltonian, time, n_steps, order, algorithm))
final_state = circuit.final_state_vector(initial_state=start_state)
correct_state = exact_state
assert fidelity(final_state, correct_state) > result_fidelity
# Make sure the time wasn't too small
assert fidelity(final_state, start_state) < 0.95 * result_fidelity
def test_simulate_trotter_simulate_controlled(hamiltonian, time, initial_state,
exact_state, order, n_steps,
algorithm, result_fidelity):
n_qubits = openfermion.count_qubits(hamiltonian)
qubits = cirq.LineQubit.range(n_qubits)
control = cirq.LineQubit(-1)
zero = [1, 0]
one = [0, 1]
start_state = (numpy.kron(zero, initial_state) +
numpy.kron(one, initial_state)) / numpy.sqrt(2)
circuit = cirq.Circuit(
simulate_trotter(qubits, hamiltonian, time, n_steps, order, algorithm,
control))
final_state = circuit.final_state_vector(initial_state=start_state)
correct_state = (numpy.kron(zero, initial_state) +
numpy.kron(one, exact_state)) / numpy.sqrt(2)
assert fidelity(final_state, correct_state) > result_fidelity
# Make sure the time wasn't too small
assert fidelity(final_state, start_state) < 0.95 * result_fidelity
def test_simulate_trotter_bad_order_raises_error():
qubits = cirq.LineQubit.range(2)
hamiltonian = openfermion.random_diagonal_coulomb_hamiltonian(2, seed=0)
time = 1.0
with pytest.raises(ValueError):
_ = next(simulate_trotter(qubits, hamiltonian, time, order=-1))
def test_simulate_trotter_omit_final_swaps():
n_qubits = 5
qubits = cirq.LineQubit.range(n_qubits)
hamiltonian = openfermion.DiagonalCoulombHamiltonian(one_body=numpy.ones(
(n_qubits, n_qubits)),
two_body=numpy.ones(
(n_qubits,
n_qubits)))
time = 1.0
circuit_with_swaps = cirq.Circuit(
simulate_trotter(qubits,
hamiltonian,
time,
order=0,
algorithm=LINEAR_SWAP_NETWORK))
circuit_without_swaps = cirq.Circuit(
simulate_trotter(qubits,
hamiltonian,
time,
order=0,
algorithm=LINEAR_SWAP_NETWORK,
omit_final_swaps=True))
assert len(circuit_without_swaps) < len(circuit_with_swaps)
circuit_with_swaps = cirq.Circuit(simulate_trotter(
qubits,
hamiltonian,
time,
order=1,
n_steps=3,
algorithm=SPLIT_OPERATOR),
strategy=cirq.InsertStrategy.NEW)
circuit_without_swaps = cirq.Circuit(simulate_trotter(
qubits,
hamiltonian,
time,
order=1,
n_steps=3,
algorithm=SPLIT_OPERATOR,
omit_final_swaps=True),
strategy=cirq.InsertStrategy.NEW)
assert len(circuit_without_swaps) < len(circuit_with_swaps)
hamiltonian = lih_hamiltonian
qubits = cirq.LineQubit.range(4)
circuit_with_swaps = cirq.Circuit(
simulate_trotter(qubits,
hamiltonian,
time,
order=0,
algorithm=LOW_RANK))
circuit_without_swaps = cirq.Circuit(
simulate_trotter(qubits,
hamiltonian,
time,
order=0,
algorithm=LOW_RANK,
omit_final_swaps=True))
assert len(circuit_without_swaps) < len(circuit_with_swaps)