def test_simulator_is_available():
backend = DummyEngine(save_commands=True)
eng = MainEngine(backend, [])
qureg = eng.allocate_qureg(2)
X | qureg[0]
S | qureg[0]
H | qureg[0]
CNOT | (qureg[0], qureg[1])
Measure | qureg[0]
qureg[0].__del__()
qureg[1].__del__()
assert len(backend.received_commands) == 9
# Test that allocate, measure, and deallocate are available.
sim = StabilizerSimulator(3)
for cmd in backend.received_commands:
assert sim.is_available(cmd)
eng = MainEngine(sim, [])
qureg = eng.allocate_qureg(3)
X | qureg[0]
S | qureg[0]
H | qureg[0]
CNOT | (qureg[0], qureg[1])
All(Measure) | qureg
with pytest.raises(Exception):
Toffoli | (qureg[0], qureg[1], qureg[2])
eng.flush()
with pytest.raises(Exception):
with Control(eng, qureg[1:]):
X | qureg[0]
eng.flush()
def test_simulator_flush():
sim = StabilizerSimulator(2)
sim._simulator = MockStabilizerSimulatorBackend()
eng = MainEngine(sim)
eng.flush()
assert sim._simulator.run_cnt == 1
def test_simulator_functional_entangle():
sim = StabilizerSimulator(6)
eng = MainEngine(sim, [])
qubits = eng.allocate_qureg(5)
# entangle all qubits:
H | qubits[0]
for qb in qubits[1:]:
CNOT | (qubits[0], qb)
# Check the probabilities
eng.flush()
assert eng.backend.get_probability('0' * len(qubits),
qubits) == pytest.approx(0.5)
assert eng.backend.get_probability('1' * len(qubits),
qubits) == pytest.approx(0.5)
# Untangle all qubits
for qb in qubits[-1::-1]:
CNOT | (qubits[0], qb)
H | qubits[0]
# Check the probabilities
eng.flush()
assert eng.backend.get_probability('0' * len(qubits),
qubits) == pytest.approx(1.0)
assert eng.backend.get_probability('1' * len(qubits),
qubits) == pytest.approx(0.0)
All(Measure) | qubits
def test_simulator_collapse_wavefunction(mapper):
sim = StabilizerSimulator(16)
engine_list = [LocalOptimizer()]
if mapper is not None:
engine_list.append(mapper)
eng = MainEngine(sim, engine_list=engine_list)
qubits = eng.allocate_qureg(4)
# unknown qubits: raises
with pytest.raises(RuntimeError):
eng.backend.collapse_wavefunction(qubits, [0] * 4)
eng.flush()
eng.backend.collapse_wavefunction(qubits, [0] * 4)
assert pytest.approx(eng.backend.get_probability([0] * 4, qubits)) == 1.
All(H) | qubits[:-1]
eng.flush()
assert pytest.approx(eng.backend.get_probability([0] * 4, qubits)) == .125
# impossible outcome: raises
prob = eng.backend.get_probability([1, 0, 1, 0], qubits)
with pytest.raises(RuntimeError):
eng.backend.collapse_wavefunction(qubits, [0] * 3 + [1])
# Make sure nothing the state of the simulator has not changed
assert pytest.approx(prob) == eng.backend.get_probability([1, 0, 1, 0],
qubits)
eng.backend.collapse_wavefunction(qubits[1:], [0, 1, 0])
probability = eng.backend.get_probability([1, 0, 1, 0], qubits)
assert probability == pytest.approx(.5)
eng.backend.set_qubits(qubits, [0] * 3 + [1])
H | qubits[0]
CNOT | (qubits[0], qubits[1])
eng.flush()
eng.backend.collapse_wavefunction([qubits[0]], [1])
probability = eng.backend.get_probability([1, 1], qubits[0:2])
assert probability == pytest.approx(1.)
def test_simulator_probability(mapper, capsys):
sim = StabilizerSimulator(6)
engine_list = [LocalOptimizer()]
if mapper is not None:
engine_list.append(mapper)
eng = MainEngine(sim, engine_list=engine_list)
qubits = eng.allocate_qureg(6)
All(H) | qubits
eng.flush()
bits = [0, 0, 1, 0, 1, 0]
for i in range(6):
assert (eng.backend.get_probability(
bits[:i], qubits[:i]) == pytest.approx(0.5**i))
extra_qubit = eng.allocate_qubit()
with pytest.raises(RuntimeError):
eng.backend.get_probability([0], extra_qubit)
del extra_qubit
All(H) | qubits
eng.flush()
assert eng.backend.get_probability('0' * len(qubits),
qubits) == pytest.approx(1.0)
assert eng.backend.get_probability('1' * len(qubits),
qubits) == pytest.approx(0.0)
All(Measure) | qubits
def test_simulator_convert_logical_to_mapped_qubits():
sim = StabilizerSimulator(2)
mapper = BasicMapperEngine()
def receive(command_list):
pass
mapper.receive = receive
eng = MainEngine(sim, [mapper])
qubit0 = eng.allocate_qubit()
qubit1 = eng.allocate_qubit()
mapper.current_mapping = {
qubit0[0].id: qubit1[0].id,
qubit1[0].id: qubit0[0].id
}
assert (sim._convert_logical_to_mapped_qureg(qubit0 + qubit1) == qubit1 +
qubit0)
def test_simulator_no_uncompute_exception():
sim = StabilizerSimulator(2)
eng = MainEngine(sim, [])
qubit = eng.allocate_qubit()
H | qubit
with pytest.raises(RuntimeError):
qubit[0].__del__()
# If you wanted to keep using the qubit, you shouldn't have deleted it.
assert qubit[0].id == -1
def test_simulator_send():
sim = StabilizerSimulator(2)
backend = DummyEngine(save_commands=True)
eng = MainEngine(backend, [sim])
qubit = eng.allocate_qubit()
H | qubit
Measure | qubit
del qubit
eng.flush()
assert len(backend.received_commands) == 5
def test_simulator_functional_measurement():
sim = StabilizerSimulator(5)
eng = MainEngine(sim, [])
qubits = eng.allocate_qureg(5)
# entangle all qubits:
H | qubits[0]
for qb in qubits[1:]:
CNOT | (qubits[0], qb)
All(Measure) | qubits
eng.flush()
bit_value_sum = sum([int(qubit) for qubit in qubits])
assert bit_value_sum == 0 or bit_value_sum == 5
def test_simulator_measure_mapped_qubit():
sim = StabilizerSimulator(1)
eng = MainEngine(sim, [])
qb1 = WeakQubitRef(engine=eng, idx=1)
qb2 = WeakQubitRef(engine=eng, idx=2)
cmd0 = Command(engine=eng, gate=Allocate, qubits=([qb1], ))
cmd1 = Command(engine=eng, gate=X, qubits=([qb1], ))
cmd2 = Command(engine=eng,
gate=Measure,
qubits=([qb1], ),
controls=[],
tags=[LogicalQubitIDTag(2)])
with pytest.raises(NotYetMeasuredError):
int(qb1)
with pytest.raises(NotYetMeasuredError):
int(qb2)
eng.send([cmd0, cmd1, cmd2])
eng.flush()
with pytest.raises(NotYetMeasuredError):
int(qb1)
assert int(qb2) == 1
def test_unavailable_methods():
sim = StabilizerSimulator(2)
eng = MainEngine(sim, [])
qureg = eng.allocate_qureg(2)
with pytest.raises(NotImplementedError):
op = QubitOperator('Z2')
eng.backend.apply_qubit_operator(op, qureg)
with pytest.raises(NotImplementedError):
op0 = QubitOperator('Z0')
eng.backend.get_expectation_value(op0, qureg)
with pytest.raises(NotImplementedError):
eng.backend.get_amplitude('00', qureg)
with pytest.raises(NotImplementedError):
wf = [0., 0., math.sqrt(0.2), math.sqrt(0.8)]
eng.backend.set_wavefunction(wf, qureg)
with pytest.raises(NotImplementedError):
eng.backend.cheat()
def run_qecc9():
#init simulator
simulator = StabilizerSimulator(12)
eng = HiQMainEngine(simulator, [])
#allocate
qubits = eng.allocate_qureg(12)
#start
print("= Encoded the qubit, state is: |0>")
#circuit
CNOT | (qubits[0], qubits[3])
CNOT | (qubits[3], qubits[0])
CNOT | (qubits[3], qubits[6])
CNOT | (qubits[3], qubits[9])
H | qubits[3]
CNOT | (qubits[3], qubits[4])
CNOT | (qubits[3], qubits[5])
H | qubits[6]
CNOT | (qubits[6], qubits[7])
CNOT | (qubits[6], qubits[8])
H | qubits[9]
CNOT | (qubits[9], qubits[10])
CNOT | (qubits[9], qubits[11])
H | qubits[3]
H | qubits[4]
H | qubits[5]
H | qubits[6]
H | qubits[7]
H | qubits[8]
H | qubits[9]
H | qubits[10]
H | qubits[11]
CNOT | (qubits[1], qubits[3])
CNOT | (qubits[1], qubits[4])
CNOT | (qubits[1], qubits[5])
CNOT | (qubits[1], qubits[6])
CNOT | (qubits[1], qubits[7])
CNOT | (qubits[1], qubits[8])
CNOT | (qubits[1], qubits[9])
CNOT | (qubits[1], qubits[10])
CNOT | (qubits[1], qubits[11])
H | qubits[3]
H | qubits[4]
H | qubits[5]
H | qubits[6]
H | qubits[7]
H | qubits[8]
H | qubits[9]
H | qubits[10]
H | qubits[11]
CNOT | (qubits[2], qubits[3])
CNOT | (qubits[2], qubits[4])
CNOT | (qubits[2], qubits[5])
CNOT | (qubits[2], qubits[6])
CNOT | (qubits[2], qubits[7])
CNOT | (qubits[2], qubits[8])
CNOT | (qubits[2], qubits[9])
CNOT | (qubits[2], qubits[10])
CNOT | (qubits[2], qubits[11])
CNOT | (qubits[9], qubits[11])
CNOT | (qubits[9], qubits[10])
H | qubits[9]
CNOT | (qubits[6], qubits[8])
CNOT | (qubits[6], qubits[7])
H | qubits[6]
CNOT | (qubits[3], qubits[5])
CNOT | (qubits[3], qubits[4])
H | qubits[3]
CNOT | (qubits[3], qubits[9])
CNOT | (qubits[3], qubits[6])
Measure | qubits[3]
#flush
eng.flush()
print("= Decoded the qubit, state is: |{}>".format(int(qubits[3])))
def test_compare_simulators():
num_cycles = 20
num_qubits = 16
num_gates = 100
num_probability_check = 100
for c in range(num_cycles):
sim = Simulator()
eng = MainEngine(sim, [])
qureg = eng.allocate_qureg(num_qubits)
sim_stab = StabilizerSimulator(num_qubits)
eng_stab = MainEngine(sim_stab, [])
qureg_stab = eng_stab.allocate_qureg(num_qubits)
for gate in range(num_gates):
r = random.randint(0, 4)
qb0 = random.randint(0, num_qubits - 1)
if r == 0:
H | qureg[qb0]
H | qureg_stab[qb0]
elif r == 1:
S | qureg[qb0]
S | qureg_stab[qb0]
elif r == 1:
X | qureg[qb0]
X | qureg_stab[qb0]
elif r == 1:
qb1 = random.randint(0, num_qubits - 1)
CNOT | (qureg[qb0], qureg[qb1])
CNOT | (qureg_stab[qb0], qureg_stab[qb1])
eng.flush()
eng_stab.flush()
for p in range(num_probability_check):
qubit_ids = set()
qubits = []
qubits_stab = []
num_qubits_for_check = random.randint(1, num_qubits)
while len(qubits) < num_qubits_for_check:
qb = random.randint(0, num_qubits - 1)
if qb not in qubit_ids:
qubit_ids.add(qb)
qubits.append(qureg[qb])
qubits_stab.append(qureg_stab[qb])
bitstring = [
random.choice('01') for _ in range(num_qubits_for_check)
]
prob = eng.backend.get_probability(bitstring, qubits)
assert pytest.approx(prob) == eng_stab.backend.get_probability(
bitstring, qubits_stab)
if prob > 0:
eng.backend.collapse_wavefunction(qubits, bitstring)
eng_stab.backend.collapse_wavefunction(qubits, bitstring)
assert eng.backend.get_probability(bitstring,
qubits) == pytest.approx(1)
assert eng_stab.backend.get_probability(
bitstring, qubits) == pytest.approx(1)
else:
with pytest.raises(RuntimeError):
eng.backend.collapse_wavefunction(qubits, bitstring)
with pytest.raises(RuntimeError):
eng_stab.backend.collapse_wavefunction(qubits, bitstring)
All(Measure) | qureg
All(Measure) | qureg_stab