def test_reset():
a, b = cirq.LineQubit.range(2)
c = cirq.Circuit(cirq.H(a), cirq.CNOT(a, b), cirq.reset(a), cirq.reset(b))
output = cirq.QasmOutput(
c.all_operations(),
tuple(sorted(c.all_qubits())),
header='Generated from Cirq!',
precision=5,
)
assert (str(output).strip() == """
// Generated from Cirq!
OPENQASM 2.0;
include "qelib1.inc";
// Qubits: [0, 1]
qreg q[2];
h q[0];
cx q[0],q[1];
reset q[0];
reset q[1];
""".strip())
def test_reset():
q = cirq.LineQubit(0)
c = cirq.Circuit(cirq.X(q), cirq.reset(q), cirq.measure(q, key="out"))
assert cirq.CliffordSimulator().sample(c)["out"][0] == 0
c = cirq.Circuit(cirq.H(q), cirq.reset(q), cirq.measure(q, key="out"))
assert cirq.CliffordSimulator().sample(c)["out"][0] == 0
c = cirq.Circuit(cirq.reset(q), cirq.measure(q, key="out"))
assert cirq.CliffordSimulator().sample(c)["out"][0] == 0
def test_reset():
q = cirq.LineQubit(0)
simulator = ccq.mps_simulator.MPSSimulator()
c = cirq.Circuit(cirq.X(q), cirq.reset(q), cirq.measure(q))
assert simulator.sample(c)['q(0)'][0] == 0
c = cirq.Circuit(cirq.H(q), cirq.reset(q), cirq.measure(q))
assert simulator.sample(c)['q(0)'][0] == 0
c = cirq.Circuit(cirq.reset(q), cirq.measure(q))
assert simulator.sample(c)['q(0)'][0] == 0
def test_reset(split):
q = cirq.LineQubit(0)
c = cirq.Circuit(cirq.X(q), cirq.reset(q), cirq.measure(q, key="out"))
sim = cirq.CliffordSimulator(split_untangled_states=split)
assert sim.sample(c)["out"][0] == 0
c = cirq.Circuit(cirq.H(q), cirq.reset(q), cirq.measure(q, key="out"))
assert sim.sample(c)["out"][0] == 0
c = cirq.Circuit(cirq.reset(q), cirq.measure(q, key="out"))
assert sim.sample(c)["out"][0] == 0
def test_reset():
q = cirq.LineQubit(0)
sampler = cirq.StabilizerSampler()
c = cirq.Circuit(cirq.X(q), cirq.reset(q), cirq.measure(q))
assert sampler.sample(c)['q(0)'][0] == 0
c = cirq.Circuit(cirq.H(q), cirq.reset(q), cirq.measure(q))
assert sampler.sample(c)['q(0)'][0] == 0
c = cirq.Circuit(cirq.reset(q), cirq.measure(q))
assert sampler.sample(c)['q(0)'][0] == 0
def _represent_operation_with_amplitude_damping_noise(
ideal_operation: Circuit,
noise_level: float,
) -> OperationRepresentation:
r"""Returns the quasi-probability representation of the input
single-qubit ``ideal_operation`` with respect to a basis of noisy
operations.
Any ideal single-qubit unitary followed by local amplitude-damping noise
of equal ``noise_level`` is assumed to be in the basis of implementable
operations.
The representation is based on the analytical result presented
in :cite:`Takagi2020`.
Args:
ideal_operation: The ideal operation (as a QPROGRAM) to represent.
noise_level: The noise level of each amplitude damping channel.
Returns:
The quasi-probability representation of the ``ideal_operation``.
.. note::
The input ``ideal_operation`` is typically a QPROGRAM with a single
gate but could also correspond to a sequence of more gates.
This is possible as long as the unitary associated to the input
QPROGRAM, followed by a single final amplitude damping channel, is
physically implementable.
.. note::
The input ``ideal_operation`` must be a ``cirq.Circuit``.
"""
if not isinstance(ideal_operation, Circuit):
raise NotImplementedError(
"The input ideal_operation must be a cirq.Circuit.", )
qubits = ideal_operation.all_qubits()
if len(qubits) == 1:
q = tuple(qubits)[0]
eta_0 = (1 + np.sqrt(1 - noise_level)) / (2 * (1 - noise_level))
eta_1 = (1 - np.sqrt(1 - noise_level)) / (2 * (1 - noise_level))
eta_2 = -noise_level / (1 - noise_level)
etas = [eta_0, eta_1, eta_2]
post_ops = [[], Z(q), reset(q)]
else:
raise ValueError( # pragma: no cover
"Only single-qubit operations are supported." # pragma: no cover
) # pragma: no cover
# Basis of implementable operations as circuits
imp_op_circuits = [ideal_operation + Circuit(op) for op in post_ops]
# Build basis_expantion
expansion = {NoisyOperation(c): a for c, a in zip(imp_op_circuits, etas)}
return OperationRepresentation(ideal_operation, expansion)
def build_circuit(qubits, params):
"""
Constructs a circuit representing a single timestep of quantum stuff.
params is a list of 6 lists, each containing nqubits floats in [0, 1).
These parameterize the circuit, such that each operation is performed
only if its relevant parameter is >= 0.5.
In order, we check the parameters, and if they are big enough we:
-Set each qubit to zero.
-Apply a CNOT gate between this qubit and its right neighbour.
-Apply H, then S, then T gates.
-Measure in the Z basis.
Returns the constructed circuit.
"""
circuit = cirq.Circuit()
circuit.append(
cirq.reset(q) for q, p in zip(qubits, params[0]) if p >= 0.5)
for qi, q in enumerate(qubits[:-1]):
if params[1][qi] >= 0.5:
circuit.append(cirq.CNOT(q, qubits[qi + 1]))
circuit.append(cirq.H(q) for q, p in zip(qubits, params[2]) if p >= 0.5)
circuit.append(cirq.S(q) for q, p in zip(qubits, params[3]) if p >= 0.5)
circuit.append(cirq.T(q) for q, p in zip(qubits, params[4]) if p >= 0.5)
circuit.append(
cirq.measure(q) for q, p in zip(qubits, params[5]) if p >= 0.5)
return circuit
def test_run_reset(dtype):
q0, q1 = cirq.LineQid.for_qid_shape((2, 3))
simulator = cirq.Simulator(dtype=dtype)
circuit = cirq.Circuit(
cirq.H(q0),
PlusGate(3, 2)(q1),
cirq.reset(q0),
cirq.measure(q0, key='m0'),
cirq.measure(q1, key='m1a'),
cirq.reset(q1),
cirq.measure(q1, key='m1b'),
)
meas = simulator.run(circuit, repetitions=100).measurements
assert np.array_equal(meas['m0'], np.zeros((100, 1)))
assert np.array_equal(meas['m1a'], np.full((100, 1), 2))
assert np.array_equal(meas['m1b'], np.zeros((100, 1)))
def test_sim_state_instance_unchanged_during_normal_sim(split: bool):
sim = SplittableCountingSimulator(split_untangled_states=split)
state = sim._create_simulation_state(0, (q0, q1))
circuit = cirq.Circuit(cirq.H(q0), cirq.CNOT(q0, q1), cirq.reset(q1))
for step in sim.simulate_moment_steps(circuit, initial_state=state):
assert step._sim_state is state
assert (step._merged_sim_state is not state) == split
def test_reset_causes_split():
args = create_container(qs2)
args.apply_operation(cirq.CNOT(q0, q1))
assert len(set(args.values())) == 2
args.apply_operation(cirq.reset(q0))
assert len(set(args.values())) == 3
assert args[q0] is not args[q1]
assert args[q0] is not args[None]
def test_reset_does_not_split_if_disabled():
args = create_container(qs2, False)
args.apply_operation(cirq.CNOT(q0, q1))
assert len(set(args.values())) == 1
args.apply_operation(cirq.reset(q0))
assert len(set(args.values())) == 1
assert args[q1] is args[q0]
assert args[None] is args[q0]
def test_reset_channel():
r = cirq.reset(cirq.LineQubit(0))
np.testing.assert_almost_equal(
cirq.channel(r),
(np.array([[1., 0.], [0., 0]]), np.array([[0., 1.], [0., 0.]])))
assert cirq.has_channel(r)
assert not cirq.has_mixture(r)
assert cirq.qid_shape(r) == (2, )
r = cirq.reset(cirq.LineQid(0, dimension=3))
np.testing.assert_almost_equal(
cirq.channel(r),
(np.array([[1, 0, 0], [0, 0, 0], [0, 0, 0]]),
np.array([[0, 1, 0], [0, 0, 0], [0, 0, 0]]),
np.array([[0, 0, 1], [0, 0, 0], [0, 0, 0]]))) # yapf: disable
assert cirq.has_channel(r)
assert not cirq.has_mixture(r)
assert cirq.qid_shape(r) == (3, )
def test_sim_state_instance_gets_changes_from_step_result(split: bool):
sim = SplittableCountingSimulator(split_untangled_states=split)
args = sim._create_act_on_args(0, (q0, q1))
circuit = cirq.Circuit(cirq.H(q0), cirq.CNOT(q0, q1), cirq.reset(q1))
for step in sim.simulate_moment_steps(circuit, initial_state=args):
assert step._sim_state is args
args = sim._create_act_on_args(0, (q0, q1))
step._sim_state = args
assert (step._merged_sim_state is not args) == split
def qdc_step(HS_step_f: Callable[[float], cirq.Circuit],
coupl_step_f: Callable[[float, float], cirq.Circuit],
epsilon: float,
gamma: float,
t: float,
qdc_trotter_number: int,
HS_trotter_factor: int = 1) -> cirq.Circuit:
'''
Circuit implementing a generic 2nd-order trotterized QDC step.
Typical parameters of QDC steps are indicated below.
Args:
HS_step_f (`function(dt)`): function returning cirq.Circuit for a
2nd order trotter step of the system evolution.
coupl_step_f (`function(gamma, dt)`): function returning the
cirq.Circuit for a 1st oder trotter step of evolution genetated by
the system-fridge coupling.
epsilon: fridge energy
gamma: coupling strength
t: coupling time
qdc_trotter_number: steps for coupling+hamiltonian 2nd order Trotter
simulation
HS_trotter_factor: multiplicative factor for number of Trotter steps
employed for the system evolution Hamiltonian simulation.
Returns:
Circuit of the cooling step. Includes final fridge reset.
---
Typical parameters:
weak coupling:
epsilon = E_transition
t >> E_transition
gamma = pi / t
trotter_steps >= 2 sqrt(1 + (E_transition + E_max)^2 /
(2 * gamma)^2 )
bang-bang (Ramsey) strong coupling:
epsilon = e_transition
t = pi / (2 * E_transition)
gamma = 2 e_transition
trotter_steps = 1
'''
dt = t / qdc_trotter_number
coupl_halfstep = coupl_step_f(gamma, dt / 2)
c = cirq.Circuit([
coupl_halfstep,
[HS_step_f(dt / HS_trotter_factor)] * HS_trotter_factor,
cirq.ZPowGate(exponent=(-dt * epsilon / np.pi))(FRIDGE),
coupl_halfstep,
]) * qdc_trotter_number
c.append(cirq.reset(FRIDGE))
return c
def test_reset_channel():
r = cirq.reset(cirq.LineQubit(0))
np.testing.assert_almost_equal(
cirq.kraus(r),
(np.array([[1.0, 0.0], [0.0, 0]]), np.array([[0.0, 1.0], [0.0, 0.0]])))
cirq.testing.assert_consistent_channel(r)
assert not cirq.has_mixture(r)
assert cirq.num_qubits(r) == 1
assert cirq.qid_shape(r) == (2, )
r = cirq.reset(cirq.LineQid(0, dimension=3))
np.testing.assert_almost_equal(
cirq.kraus(r),
(
np.array([[1, 0, 0], [0, 0, 0], [0, 0, 0]]),
np.array([[0, 1, 0], [0, 0, 0], [0, 0, 0]]),
np.array([[0, 0, 1], [0, 0, 0], [0, 0, 0]]),
),
) # yapf: disable
cirq.testing.assert_consistent_channel(r)
assert not cirq.has_mixture(r)
assert cirq.qid_shape(r) == (3, )
def test_more_unitary_gate_conversions():
for p in [1, 1j, -1, -1j]:
assert_unitary_gate_converts_correctly(p *
cirq.DensePauliString("IXYZ"))
assert_unitary_gate_converts_correctly(
(p * cirq.DensePauliString("IXYZ")).controlled(1))
a, b = cirq.LineQubit.range(2)
c, _ = cirq_circuit_to_stim_data(
cirq.Circuit(cirq.H(a), cirq.CNOT(a, b), cirq.measure(a, b),
cirq.reset(a)))
assert (str(c).strip() == """
H 0
CX 0 1
M 0 1
R 0
""".strip())
def test_simulate_moment_steps_qudits(dtype):
q0, q1 = cirq.LineQid.for_qid_shape((2, 3))
circuit = cirq.Circuit(
PlusGate(2, 1)(q0),
PlusGate(3, 1)(q1),
cirq.reset(q1),
PlusGate(3, 1)(q1),
)
simulator = cirq.DensityMatrixSimulator(dtype=dtype)
for i, step in enumerate(simulator.simulate_moment_steps(circuit)):
assert cirq.qid_shape(step) == (2, 3)
if i == 0:
np.testing.assert_almost_equal(step.density_matrix(), np.diag([0, 0, 0, 0, 1, 0]))
elif i == 1:
np.testing.assert_almost_equal(step.density_matrix(), np.diag([0, 0, 0, 1, 0, 0]))
else:
np.testing.assert_almost_equal(step.density_matrix(), np.diag([0, 0, 0, 0, 1, 0]))
def _get_noise_proto_pairs():
q0 = cirq.GridQubit(0, 0)
pairs = [
# Depolarization.
(cirq.Circuit(cirq.depolarize(p=0.3)(q0)),
_build_op_proto("DP", ['p'], [0.3], ['0_0'])),
# Asymmetric depolarization.
(cirq.Circuit(
cirq.asymmetric_depolarize(p_x=0.1, p_y=0.2, p_z=0.3)(q0)),
_build_op_proto("ADP", ['p_x', 'p_y', 'p_z'], [0.1, 0.2, 0.3],
['0_0'])),
# Generalized Amplitude damp.
(cirq.Circuit(cirq.generalized_amplitude_damp(p=0.1, gamma=0.2)(q0)),
_build_op_proto("GAD", ['p', 'gamma'], [0.1, 0.2], ['0_0'])),
# Amplitude damp.
(cirq.Circuit(cirq.amplitude_damp(gamma=0.1)(q0)),
_build_op_proto("AD", ['gamma'], [0.1], ['0_0'])),
# Reset.
(cirq.Circuit(cirq.reset(q0)), _build_op_proto("RST", [], [],
['0_0'])),
# Phase damp.
(cirq.Circuit(cirq.phase_damp(gamma=0.1)(q0)),
_build_op_proto("PD", ['gamma'], [0.1], ['0_0'])),
# Phase flip.
(cirq.Circuit(cirq.phase_flip(p=0.1)(q0)),
_build_op_proto("PF", ['p'], [0.1], ['0_0'])),
# Bit flip.
(cirq.Circuit(cirq.bit_flip(p=0.1)(q0)),
_build_op_proto("BF", ['p'], [0.1], ['0_0']))
]
return pairs
def _get_noise_proto_pairs():
q0 = cirq.GridQubit(0, 0)
pairs = [
# Depolarization.
(cirq.Circuit(cirq.depolarize(p=0.3)(q0)),
_build_op_proto("DP", ['p'], [0.3], ['0_0'])),
# Asymmetric depolarization.
(cirq.Circuit(
cirq.asymmetric_depolarize(p_x=0.1, p_y=0.2, p_z=0.3)(q0)),
_build_op_proto("ADP", ['p_x', 'p_y', 'p_z'], [0.1, 0.2, 0.3],
['0_0'])),
# Amplitude damp.
(cirq.Circuit(cirq.amplitude_damp(gamma=0.1)(q0)),
_build_op_proto("AD", ['gamma'], [0.1], ['0_0'])),
# Reset.
(cirq.Circuit(cirq.reset(q0)), _build_op_proto("RST", [], [], ['0_0']))
]
return pairs
import cirq
qubits = cirq.LineQubit.range(3)
for i in range(200):
def CEntang():
global qubits
yield cirq.H(qubits[1]), cirq.X(qubits[0])
yield cirq.CX(qubits[1], qubits[2])
yield cirq.CX(qubits[0], qubits[1])
yield cirq.CX(qubits[1], qubits[2])
yield cirq.Moment(cirq.measure(qubits[0], key="q1"),
cirq.measure(qubits[2], key="q2"))
circuit = cirq.Circuit()
circuit.append(CEntang())
print(circuit)
simulate = cirq.Simulator()
result = simulate.run(circuit, repetitions=1000)
print(result.multi_measurement_histogram(keys=["q1", "q2"]))
cirq.reset(qubits[0])
cirq.reset(qubits[1])
print(result)
#cirq.plot_state_histogram(result)
def _decompose_(self, qubits):
yield cirq.measure(qubits[0], key='inner1')
yield cirq.measure(qubits[1], key='inner2')
yield cirq.reset(qubits[0])
def test_reset_channel_equality():
assert cirq.reset(cirq.LineQubit(0)).gate == cirq.ResetChannel()
assert cirq.reset(cirq.LineQid(0, 3)).gate == cirq.ResetChannel(3)
def test_reset_stabilizer():
assert cirq.has_stabilizer_effect(cirq.reset(cirq.LineQubit(0)))