def test_no_touch_single_sqrt_iswap():
a, b = cirq.LineQubit.range(2)
assert_optimizes(
before=cirq.Circuit([
cirq.Moment([cirq.SQRT_ISWAP(a, b).with_tags('mytag')]),
]),
expected=cirq.Circuit([
cirq.Moment([cirq.SQRT_ISWAP(a, b).with_tags('mytag')]),
]),
)
def test_works_with_tags():
a, b = cirq.LineQubit.range(2)
assert_optimizes(
before=cirq.Circuit([
cirq.Moment([cirq.SQRT_ISWAP(a, b).with_tags('mytag1')]),
cirq.Moment([cirq.SQRT_ISWAP(a, b).with_tags('mytag2')]),
cirq.Moment([cirq.SQRT_ISWAP_INV(a, b).with_tags('mytag3')]),
]),
expected=cirq.Circuit([cirq.Moment([cirq.SQRT_ISWAP(a, b)])]),
)
def test_incremental_simulate(multiprocess):
q0, q1 = cirq.LineQubit.range(2)
circuits = [
rqcg.random_rotations_between_two_qubit_circuit(
q0,
q1,
depth=100,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
) for _ in range(20)
]
cycle_depths = np.arange(3, 100, 9)
if multiprocess:
pool = multiprocessing.Pool()
else:
pool = None
start = time.perf_counter()
df_ref = _ref_simulate_2q_xeb_circuits(
circuits=circuits,
cycle_depths=cycle_depths,
pool=pool,
)
end1 = time.perf_counter()
df = simulate_2q_xeb_circuits(circuits=circuits,
cycle_depths=cycle_depths,
pool=pool)
end2 = time.perf_counter()
if pool is not None:
pool.terminate()
print("\nnew:", end2 - end1, "old:", end1 - start)
pd.testing.assert_frame_equal(df_ref, df)
def _get_random_circuit(qubits, *, n_moments=10, random_state=52):
return cirq.experiments.random_rotations_between_grid_interaction_layers_circuit(
qubits=qubits,
depth=n_moments,
seed=random_state,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
) + cirq.measure(*qubits, key='z')
def test_simulate_2q_xeb_circuits():
q0, q1 = cirq.LineQubit.range(2)
circuits = [
rqcg.random_rotations_between_two_qubit_circuit(
q0,
q1,
depth=50,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
) for _ in range(2)
]
cycle_depths = np.arange(3, 50, 9)
df = simulate_2q_xeb_circuits(
circuits=circuits,
cycle_depths=cycle_depths,
)
assert len(df) == len(cycle_depths) * len(circuits)
for (circuit_i, cycle_depth), row in df.iterrows():
assert 0 <= circuit_i < len(circuits)
assert cycle_depth in cycle_depths
assert len(row['pure_probs']) == 4
assert np.isclose(np.sum(row['pure_probs']), 1)
with multiprocessing.Pool() as pool:
df2 = simulate_2q_xeb_circuits(circuits, cycle_depths, pool=pool)
pd.testing.assert_frame_equal(df, df2)
def cphase_symbols_to_sqrt_iswap(a, b, turns):
"""Version of cphase_to_sqrt_iswap that works with symbols.
Note that the formulae contained below will need to be flattened
into a sweep before serializing.
"""
theta = sympy.Mod(turns, 2.0) * sympy.pi
# -1 if theta > pi. Adds a hacky fudge factor so theta=pi is not 0
sign = sympy.sign(sympy.pi - theta + 1e-9)
# For sign = 1: theta. For sign = -1, 2pi-theta
theta_prime = (sympy.pi - sign * sympy.pi) + sign * theta
phi = sympy.asin(np.sqrt(2) * sympy.sin(theta_prime / 4))
xi = sympy.atan(sympy.tan(phi) / np.sqrt(2))
yield cirq.rz(sign * 0.5 * theta_prime).on(a)
yield cirq.rz(sign * 0.5 * theta_prime).on(b)
yield cirq.rx(xi).on(a)
yield cirq.X(b)**(-sign * 0.5)
yield cirq.SQRT_ISWAP_INV(a, b)
yield cirq.rx(-2 * phi).on(a)
yield cirq.SQRT_ISWAP(a, b)
yield cirq.rx(xi).on(a)
yield cirq.X(b)**(sign * 0.5)
def test_sample_2q_xeb_circuits():
q0 = cirq.NamedQubit('a')
q1 = cirq.NamedQubit('b')
circuits = [
rqcg.random_rotations_between_two_qubit_circuit(
q0,
q1,
depth=20,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
) for _ in range(2)
]
cycle_depths = np.arange(3, 20, 6)
df = sample_2q_xeb_circuits(
sampler=cirq.Simulator(),
circuits=circuits,
cycle_depths=cycle_depths,
shuffle=np.random.RandomState(10),
)
assert len(df) == len(cycle_depths) * len(circuits)
for (circuit_i, cycle_depth), row in df.iterrows():
assert 0 <= circuit_i < len(circuits)
assert cycle_depth in cycle_depths
assert len(row['sampled_probs']) == 4
assert np.isclose(np.sum(row['sampled_probs']), 1)
def test_simplifies_sqrt_iswap():
a, b = cirq.LineQubit.range(2)
assert_optimizes(
before=cirq.Circuit([
# SQRT_ISWAP**8 == Identity
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
cirq.Moment([cirq.SQRT_ISWAP(a, b)]),
]),
expected=cirq.Circuit([cirq.Moment([cirq.SQRT_ISWAP(a, b)])]),
)
def rewriter_replace_with_decomp(op: 'cirq.CircuitOperation') -> 'cirq.OP_TREE':
nonlocal component_id
component_id = component_id + 1
tag = f'{component_id}'
if len(op.qubits) == 1:
return [cirq.T(op.qubits[0]).with_tags(tag)]
one_layer = [op.with_tags(tag) for op in cirq.T.on_each(*op.qubits)]
two_layer = [cirq.SQRT_ISWAP(*op.qubits).with_tags(tag)]
return [one_layer, two_layer, one_layer]
def swap_to_sqrt_iswap(a, b, turns):
"""Implement the evolution of a hopping term using two sqrt_iswap gates and single qubit gates.
Output unitary:
[[1, 0, 0, 0],
[0, g·c, -i·g·s, 0],
[0, -i·g·s, g·c, 0],
[0, 0, 0, 1]]
where c = cos(theta) and s = sin(theta).
Args:
a: the first qubit
b: the second qubit
turns: The rotational angle that specifies the gate, where
c = cos(π·t/2), s = sin(π·t/2), g = exp(i·π·t/2).
Yields:
A `cirq.OP_TREE` representing the decomposition.
"""
if not isinstance(turns, sympy.Basic) and _near_mod_n(turns, 1.0, 2):
# Decomposition for cirq.SWAP
yield cirq.Y(a)**0.5
yield cirq.Y(b)**0.5
yield cirq.SQRT_ISWAP(a, b)
yield cirq.Y(a)**-0.5
yield cirq.Y(b)**-0.5
yield cirq.SQRT_ISWAP(a, b)
yield cirq.X(a)**-0.5
yield cirq.X(b)**-0.5
yield cirq.SQRT_ISWAP(a, b)
yield cirq.X(a)**0.5
yield cirq.X(b)**0.5
return
yield cirq.Z(a)**1.25
yield cirq.Z(b)**-0.25
yield cirq.ISWAP(a, b)**-0.5
yield cirq.Z(a)**(-turns / 2 + 1)
yield cirq.Z(b)**(turns / 2)
yield cirq.ISWAP(a, b)**-0.5
yield cirq.Z(a)**(turns / 2 - 0.25)
yield cirq.Z(b)**(turns / 2 + 0.25)
yield cirq.CZ.on(a, b)**(-turns)
def test_simulate_circuit_length_validation():
q0, q1 = cirq.LineQubit.range(2)
circuits = [
rqcg.random_rotations_between_two_qubit_circuit(
q0,
q1,
depth=10, # not long enough!
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
) for _ in range(2)
]
cycle_depths = np.arange(3, 50, 9)
with pytest.raises(ValueError, match='.*not long enough.*'):
_ = simulate_2q_xeb_circuits(circuits=circuits,
cycle_depths=cycle_depths)
def test_random_device_placer_small_device():
topo = cirq.TiltedSquareLattice(3, 3)
qubits = sorted(topo.nodes_to_gridqubits().values())
circuit = cirq.experiments.random_rotations_between_grid_interaction_layers_circuit(
qubits, depth=8, two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b)
)
qp = cg.RandomDevicePlacer()
with pytest.raises(cg.CouldNotPlaceError):
qp.place_circuit(
circuit,
problem_topology=topo,
shared_rt_info=cg.SharedRuntimeInfo(run_id='1', device=cg.Foxtail),
rs=np.random.RandomState(1),
)
def circuits_cycle_depths_sampled_df():
q0, q1 = cirq.LineQubit.range(2)
circuits = [
rqcg.random_rotations_between_two_qubit_circuit(
q0,
q1,
depth=50,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
seed=52) for _ in range(2)
]
cycle_depths = np.arange(10, 40 + 1, 10)
sampled_df = sample_2q_xeb_circuits(sampler=cirq.Simulator(seed=53),
circuits=circuits,
cycle_depths=cycle_depths)
return circuits, cycle_depths, sampled_df
def test_characterize_phased_fsim_parameters_with_xeb():
q0, q1 = cirq.LineQubit.range(2)
rs = np.random.RandomState(52)
circuits = [
rqcg.random_rotations_between_two_qubit_circuit(
q0,
q1,
depth=20,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b),
seed=rs,
) for _ in range(2)
]
cycle_depths = np.arange(3, 20, 6)
sampled_df = sample_2q_xeb_circuits(
sampler=cirq.Simulator(seed=rs),
circuits=circuits,
cycle_depths=cycle_depths,
progress_bar=None,
)
# only optimize theta so it goes faster.
options = SqrtISwapXEBOptions(
characterize_theta=True,
characterize_gamma=False,
characterize_chi=False,
characterize_zeta=False,
characterize_phi=False,
)
p_circuits = [
parameterize_circuit(circuit, options) for circuit in circuits
]
with multiprocessing.Pool() as pool:
result = characterize_phased_fsim_parameters_with_xeb(
sampled_df=sampled_df,
parameterized_circuits=p_circuits,
cycle_depths=cycle_depths,
options=options,
# speed up with looser tolerances:
fatol=1e-2,
xatol=1e-2,
pool=pool,
)
opt_res = result.optimization_results[(q0, q1)]
assert np.abs(opt_res.x[0] + np.pi / 4) < 0.1
assert np.abs(opt_res.fun) < 0.1 # noiseless simulator
assert len(result.fidelities_df) == len(cycle_depths)
assert np.all(result.fidelities_df['fidelity'] > 0.95)
def cphase_to_sqrt_iswap(a, b, turns):
"""Implement a C-Phase gate using two sqrt ISWAP gates and single-qubit
operations. The circuit is equivalent to cirq.CZPowGate(exponent=turns).
Output unitary:
[1 0 0 0],
[0 1 0 0],
[0 0 1 0],
[0 0 0 e^{i turns pi}].
Args:
a: the first qubit
b: the second qubit
turns: Exponent specifying the evolution time in number of rotations.
"""
theta = (turns % 2) * np.pi
if 0 <= theta <= np.pi:
sign = 1.0
theta_prime = theta
elif np.pi < theta < 2 * np.pi:
sign = -1.0
theta_prime = 2 * np.pi - theta
if np.isclose(theta, np.pi):
# If we are close to pi, just set values manually to avoid possible
# numerical errors with arcsin of greater than 1.0 (Ahem, Windows).
phi = np.pi / 2
xi = np.pi / 2
else:
phi = np.arcsin(np.sqrt(2) * np.sin(theta_prime / 4))
xi = np.arctan(np.tan(phi) / np.sqrt(2))
yield cirq.rz(sign * 0.5 * theta_prime).on(a)
yield cirq.rz(sign * 0.5 * theta_prime).on(b)
yield cirq.rx(xi).on(a)
yield cirq.X(b)**(-sign * 0.5)
yield cirq.SQRT_ISWAP_INV(a, b)
yield cirq.rx(-2 * phi).on(a)
yield cirq.SQRT_ISWAP(a, b)
yield cirq.rx(xi).on(a)
yield cirq.X(b)**(sign * 0.5)
# Corrects global phase
yield cirq.global_phase_operation(np.exp(sign * theta_prime * 0.25j))
def test_device_missing_metadata():
class BadDevice(cirq.Device):
pass
topo = cirq.TiltedSquareLattice(3, 3)
qubits = sorted(topo.nodes_to_gridqubits().values())
circuit = cirq.experiments.random_rotations_between_grid_interaction_layers_circuit(
qubits,
depth=8,
two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b))
qp = cg.RandomDevicePlacer()
with pytest.raises(ValueError):
qp.place_circuit(
circuit,
problem_topology=topo,
shared_rt_info=cg.SharedRuntimeInfo(run_id='1',
device=BadDevice()),
rs=np.random.RandomState(1),
)
def test_random_device_placer_tilted_square_lattice():
topo = cirq.TiltedSquareLattice(4, 2)
qubits = sorted(topo.nodes_to_gridqubits().values())
circuit = cirq.experiments.random_rotations_between_grid_interaction_layers_circuit(
qubits, depth=8, two_qubit_op_factory=lambda a, b, _: cirq.SQRT_ISWAP(a, b)
)
assert not all(q in cg.Sycamore23.qubit_set() for q in circuit.all_qubits())
qp = cg.RandomDevicePlacer()
circuit2, mapping = qp.place_circuit(
circuit,
problem_topology=topo,
shared_rt_info=cg.SharedRuntimeInfo(run_id='1', device=cg.Sycamore23),
rs=np.random.RandomState(1),
)
assert circuit is not circuit2
assert circuit != circuit2
assert all(q in cg.Sycamore23.qubit_set() for q in circuit2.all_qubits())
for k, v in mapping.items():
assert k != v
