def _generate_experiment_programs(
tomo_experiment: TomographyExperiment,
active_reset: bool = False) -> Tuple[List[Program], List[List[int]]]:
"""
Generate the programs necessary to estimate the observables in a TomographyExperiment.
Grouping of settings to be run in parallel, e.g. by a call to group_experiments, should be
done before this function is called.
.. CAUTION::
One must be careful with compilation of the output programs before the appropriate MEASURE
instructions are added, because compilation may re-index the qubits so that
the output list of `measure_qubits` no longer accurately indexes the qubits that
should be measured.
:param tomo_experiment: a single TomographyExperiment to be translated to a series of programs
that, when run serially, can be used to estimate each of its observables.
:param active_reset: whether or not to begin the program by actively resetting. If true,
execution of each of the returned programs in a loop on the QPU will generally be faster.
:return: a list of programs along with a corresponding list of the groups of qubits that are
measured by that program. The returned programs may be run on a qc after measurement
instructions are added for the corresponding group of qubits in meas_qubits, or by a call
to `qc.run_symmetrized_readout` -- see :func:`raw_estimate_observables` for possible usage.
"""
# Outer loop over a collection of grouped settings for which we can simultaneously estimate.
programs = []
meas_qubits = []
for settings in tomo_experiment:
# Prepare a state according to the amalgam of all setting.in_state
total_prog = Program()
if active_reset:
total_prog += RESET()
max_weight_in_state = _max_weight_state(setting.in_state
for setting in settings)
if max_weight_in_state is None:
raise ValueError(
"Input states are not compatible. Re-group the experiment settings "
"so that groups of parallel settings have compatible input states."
)
for oneq_state in max_weight_in_state.states:
total_prog += _one_q_state_prep(oneq_state)
# Add in the program
total_prog += tomo_experiment.program
# Prepare for measurement state according to setting.out_operator
max_weight_out_op = _max_weight_operator(setting.out_operator
for setting in settings)
if max_weight_out_op is None:
raise ValueError(
"Observables not compatible. Re-group the experiment settings "
"so that groups of parallel settings have compatible observables."
)
for qubit, op_str in max_weight_out_op:
total_prog += _local_pauli_eig_meas(op_str, qubit)
programs.append(total_prog)
meas_qubits.append(max_weight_out_op.get_qubits())
return programs, meas_qubits
def test_qc_joint_expectation(forest):
device = NxDevice(nx.complete_graph(2))
qc = QuantumComputer(
name="testy!", qam=QVM(connection=forest), device=device, compiler=DummyCompiler()
)
# |01> state program
p = Program()
p += RESET()
p += X(0)
p.wrap_in_numshots_loop(10)
# ZZ experiment
sz = ExperimentSetting(
in_state=sZ(0) * sZ(1), out_operator=sZ(0) * sZ(1), additional_expectations=[[0], [1]]
)
e = Experiment(settings=[sz], program=p)
results = qc.experiment(e)
# ZZ expectation value for state |01> is -1
assert np.isclose(results[0].expectation, -1)
assert np.isclose(results[0].std_err, 0)
assert results[0].total_counts == 40
# Z0 expectation value for state |01> is -1
assert np.isclose(results[0].additional_results[0].expectation, -1)
assert results[0].additional_results[1].total_counts == 40
# Z1 expectation value for state |01> is 1
assert np.isclose(results[0].additional_results[1].expectation, 1)
assert results[0].additional_results[1].total_counts == 40
def test_validate_supported_quil_reset_qubit():
prog = Program(
RESET(2),
)
with pytest.raises(ValueError):
validate_supported_quil(prog)
assert not prog.is_supported_on_qpu()
def test_validate_protoquil_reset_qubit():
prog = Program(
RESET(2),
)
with pytest.raises(ValueError):
validate_protoquil(prog)
assert not prog.is_protoquil()
def initialize_toric_code(primal: nx.Graph, dual: nx.Graph, distance: nx.Graph, L: int, trials=100) -> Program:
""" Initializes the toric code into an appropriate eigenstate of the stabilizers, assuming
the qubits begin in the state |0> \tensor |0> \tensor ... \tensor |0> before initialization.
:param primal, dual, distance: primal/dual/distance graphs returned by construct_toric_code
:param L: number of physical qubits on one side of the lattice
:param trials: number of trials to obtain an even number of qubit errors
:returns: program representing correction operation
"""
# A hacky way to ensure the initialization works:
# run the syndrome extraction until we return an even
# number of errors (okay for small graphs)
for t in range(trials):
# Set up programs, and reset qubits if needed
primal_initial = Program() + RESET()
# Perform syndrome extraction on primal graph
primal_faulty_nodes = syndrome_extraction(primal, L, primal_initial, "X")
test = (len(primal_faulty_nodes) % 2 == 0)
if test:
break
assert test, "Failed to find even number of faulty nodes for primal and dual graphs"
# With an even number of faulty nodes, we can now run the mwpm algorithm
# and correct the -1 eigenvalues
primal_correction_paths = mwpm(primal, distance, L, primal_faulty_nodes)
# Construct pyquil program to carry out corrections
primal_correct_pq = apply_operation(primal_correction_paths, primal, Z)
return primal_correct_pq
def test_qc_joint_expectation(client_configuration: QCSClientConfiguration,
dummy_compiler: DummyCompiler):
qc = QuantumComputer(name="testy!",
qam=QVM(client_configuration=client_configuration),
compiler=dummy_compiler)
# |01> state program
p = Program()
p += RESET()
p += X(0)
p.wrap_in_numshots_loop(10)
# ZZ experiment
sz = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0) * sZ(1)),
out_operator=sZ(0) * sZ(1),
additional_expectations=[[0], [1]])
e = Experiment(settings=[sz], program=p)
results = qc.run_experiment(e)
# ZZ expectation value for state |01> is -1
assert np.isclose(results[0].expectation, -1)
assert np.isclose(results[0].std_err, 0)
assert results[0].total_counts == 40
# Z0 expectation value for state |01> is -1
assert np.isclose(results[0].additional_results[0].expectation, -1)
assert results[0].additional_results[1].total_counts == 40
# Z1 expectation value for state |01> is 1
assert np.isclose(results[0].additional_results[1].expectation, 1)
assert results[0].additional_results[1].total_counts == 40
def test_qc_expectation_on_qvm(client_configuration: QCSClientConfiguration, dummy_compiler: DummyCompiler):
# regression test for https://github.com/rigetti/forest-tutorials/issues/2
qc = QuantumComputer(name="testy!", qam=QVM(client_configuration=client_configuration), compiler=dummy_compiler)
p = Program()
theta = p.declare("theta", "REAL")
p += RESET()
p += RY(theta, 0)
p.wrap_in_numshots_loop(10000)
sx = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0)), out_operator=sX(0))
e = Experiment(settings=[sx], program=p)
thetas = [-np.pi / 2, 0.0, np.pi / 2]
results = []
# Verify that multiple calls to qc.experiment with the same experiment backed by a QVM that
# requires_exectutable does not raise an exception.
for theta in thetas:
results.append(qc.experiment(e, memory_map={"theta": [theta]}))
assert np.isclose(results[0][0].expectation, -1.0, atol=0.01)
assert np.isclose(results[0][0].std_err, 0)
assert results[0][0].total_counts == 20000
# bounds on atol and std_err here are a little loose to try and avoid test flakiness.
assert np.isclose(results[1][0].expectation, 0.0, atol=0.1)
assert results[1][0].std_err < 0.01
assert results[1][0].total_counts == 20000
assert np.isclose(results[2][0].expectation, 1.0, atol=0.01)
assert np.isclose(results[2][0].std_err, 0)
assert results[2][0].total_counts == 20000
def test_qc_expectation(client_configuration: QCSClientConfiguration, dummy_compiler: DummyCompiler):
qc = QuantumComputer(name="testy!", qam=QVM(client_configuration=client_configuration), compiler=dummy_compiler)
# bell state program
p = Program()
p += RESET()
p += H(0)
p += CNOT(0, 1)
p.wrap_in_numshots_loop(10)
# XX, YY, ZZ experiment
sx = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0) * sZ(1)), out_operator=sX(0) * sX(1))
sy = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0) * sZ(1)), out_operator=sY(0) * sY(1))
sz = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0) * sZ(1)), out_operator=sZ(0) * sZ(1))
e = Experiment(settings=[sx, sy, sz], program=p)
results = qc.experiment(e)
# XX expectation value for bell state |00> + |11> is 1
assert np.isclose(results[0].expectation, 1)
assert np.isclose(results[0].std_err, 0)
assert results[0].total_counts == 40
# YY expectation value for bell state |00> + |11> is -1
assert np.isclose(results[1].expectation, -1)
assert np.isclose(results[1].std_err, 0)
assert results[1].total_counts == 40
# ZZ expectation value for bell state |00> + |11> is 1
assert np.isclose(results[2].expectation, 1)
assert np.isclose(results[2].std_err, 0)
assert results[2].total_counts == 40
def test_qc_joint_calibration(client_configuration: QCSClientConfiguration):
# noise model with 95% symmetrized readout fidelity per qubit
noise_model = asymmetric_ro_model([0, 1], 0.945, 0.955)
qc = get_qc("2q-qvm", client_configuration=client_configuration)
qc.qam.noise_model = noise_model
# |01> state program
p = Program()
p += RESET()
p += X(0)
p.wrap_in_numshots_loop(10000)
# ZZ experiment
sz = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0) * sZ(1)),
out_operator=sZ(0) * sZ(1),
additional_expectations=[[0], [1]])
e = Experiment(settings=[sz], program=p)
results = qc.run_experiment(e)
# ZZ expectation value for state |01> with 95% RO fid on both qubits is about -0.81
assert np.isclose(results[0].expectation, -0.81, atol=0.01)
assert results[0].total_counts == 40000
# Z0 expectation value for state |01> with 95% RO fid on both qubits is about -0.9
assert np.isclose(results[0].additional_results[0].expectation,
-0.9,
atol=0.01)
assert results[0].additional_results[1].total_counts == 40000
# Z1 expectation value for state |01> with 95% RO fid on both qubits is about 0.9
assert np.isclose(results[0].additional_results[1].expectation,
0.9,
atol=0.01)
assert results[0].additional_results[1].total_counts == 40000
def _run_program(self, program):
program = program.copy()
if self.qpu:
# time to go through the compiler. whee!
pragma = Program(
[Pragma("INITIAL_REWIRING", ['"PARTIAL"']),
RESET()])
program = pragma + program
program = self._wrap_program(program)
nq_program = self._qc.compiler.quil_to_native_quil(program)
gate_count = sum(1 for instr in nq_program
if isinstance(instr, Gate))
executable = self._qc.compiler.native_quil_to_executable(
nq_program)
results = self._qc.run(executable=executable)
else:
program = self._wrap_program(program)
gate_count = len(program)
results = self._qc.run(program)
info = {
"gate_count": gate_count
} # compiled length for qpu, uncompiled for qvm
return results, info
def get_calibration_program(observable: PauliTerm, noisy_program: Program = None,
active_reset: bool = False) -> Program:
"""
Program required for calibrating the given observable.
:param observable: observable to calibrate
:param noisy_program: a program with readout and gate noise defined; only useful for QVM
:param active_reset: whether or not to begin the program by actively resetting. If true,
execution of each of the returned programs in a loop on the QPU will generally be faster.
:return: Program performing the calibration
"""
calibr_prog = Program()
if active_reset:
calibr_prog += RESET()
# Inherit any noisy attributes from noisy_program, including gate definitions
# and applications which can be handy in simulating noisy channels
if noisy_program is not None:
# Inherit readout error instructions from main Program
readout_povm_instruction = [i for i in noisy_program.out().split('\n')
if 'PRAGMA READOUT-POVM' in i]
calibr_prog += readout_povm_instruction
# Inherit any definitions of noisy gates from main Program
kraus_instructions = [i for i in noisy_program.out().split('\n') if 'PRAGMA ADD-KRAUS' in i]
calibr_prog += kraus_instructions
# Prepare the +1 eigenstate for the out operator
for q, op in observable.operations_as_set():
calibr_prog += _one_q_pauli_prep(label=op, index=0, qubit=q)
# Measure the out operator in this state
for q, op in observable.operations_as_set():
calibr_prog += _local_pauli_eig_meas(op, q)
return calibr_prog
def test_validate_protoquil_reset_first():
prog = Program(
H(0),
RESET(),
)
with pytest.raises(ValueError):
validate_protoquil(prog)
assert not prog.is_protoquil()
def test_validate_protoquil_with_pragma():
prog = Program(
RESET(),
H(1),
Pragma('DELAY'),
MEASURE(1)
)
assert prog.is_protoquil()
def test_validate_supported_quil_with_pragma():
prog = Program(
RESET(),
H(1),
Pragma('DELAY'),
MEASURE(1, None)
)
assert prog.is_supported_on_qpu()
def generate_rigetti(self):
import pyquil
from pyquil.quil import Program
from pyquil.gates import H, RZ, RX, RY, CNOT, MEASURE, RESET
from pyquil.api import get_qc
self.rigetti_circuits_list=[]
print("Creating Pyquil program list...")
self.logfile.write("Creating Pyquil program list...")
for circuit in self.circuits_list:
p = pyquil.Program(RESET()) #compressed program
ro = p.declare('ro', memory_type='BIT', memory_size=self.num_qubits)
for gate in circuit.gates:
if gate.name in "H":
p.inst(pyquil.gates.H(gate.qubits[0]))
elif gate.name in "RZ":
p.inst(pyquil.gates.RZ(gate.angles[0],gate.qubits[0]))
elif gate.name in "RX":
p.inst(pyquil.gates.RX(gate.angles[0],gate.qubits[0]))
elif gate.name in "CNOT":
p.inst(pyquil.gates.CNOT(gate.qubits[0],gate.qubits[1]))
for i in range(self.num_qubits):
p.inst(pyquil.gates.MEASURE(i,ro[i]))
p.wrap_in_numshots_loop(self.shots)
self.rigetti_circuits_list.append(p)
if "y" in self.compile:
qc=get_qc(self.device_choice)
if self.JZ != 0 and self.JX==self.JY==0 and self.h_ext!=0 and self.ext_dir=="X" and self.auto_ds_compile=="y":
#TFIM
print("TFIM detected, enabling DS compiler")
self.logfile.write("TFIM detected, enabling DS compiler")
temp=[]
for circuit in self.rigetti_circuits_list:
temp.append(ds_compile(circuit,self.backend,self.shots))
self.rigetti_circuits_list=temp
elif self.default_compiler in "ds":
temp=[]
print("Compiling circuits...")
self.logfile.write("Compiling circuits...")
for circuit in self.rigetti_circuits_list:
temp.append(ds_compile(circuit,self.backend,self.shots))
self.rigetti_circuits_list=temp
print("Circuits compiled successfully")
self.logfile.write("Circuits compiled successfully")
elif self.default_compiler in "native":
temp=[]
print("Transpiling circuits...")
self.logfile.write("Transpiling circuits...")
for circuit in self.rigetti_circuits_list:
circ = qc.compile(circuit)
temp.append(circ)
self.rigetti_circuits_list=temp
print("Circuits transpiled successfully")
self.logfile.write("Circuits transpiled successfully")
print("Pyquil program list created successfully")
self.logfile.write("Pyquil program list created successfully")
def pre_expval(self):
"""Run the QVM"""
# pylint: disable=attribute-defined-outside-init
for e in self.expval_queue:
wire = [e.wires[0]]
if e.name == 'PauliX':
# X = H.Z.H
self.apply('Hadamard', wire, [])
elif e.name == 'PauliY':
# Y = (HS^)^.Z.(HS^) and S^=SZ
self.apply('PauliZ', wire, [])
self.apply('S', wire, [])
self.apply('Hadamard', wire, [])
elif e.name == 'Hadamard':
# H = Ry(-pi/4)^.Z.Ry(-pi/4)
self.apply('RY', wire, [-np.pi/4])
elif e.name == 'Hermitian':
# For arbitrary Hermitian matrix H, let U be the unitary matrix
# that diagonalises it, and w_i be the eigenvalues.
H = e.parameters[0]
Hkey = tuple(H.flatten().tolist())
if Hkey in self._eigs:
# retrieve eigenvectors
U = self._eigs[Hkey]['eigvec']
else:
# store the eigenvalues corresponding to H
# in a dictionary, so that they do not need to
# be calculated later
w, U = np.linalg.eigh(H)
self._eigs[Hkey] = {'eigval': w, 'eigvec': U}
# Perform a change of basis before measuring by applying U^ to the circuit
self.apply('QubitUnitary', wire, [U.conj().T])
prag = Program(Pragma('INITIAL_REWIRING', ['"PARTIAL"']))
if self.active_reset:
prag += RESET()
self.prog = prag + self.prog
qubits = list(self.prog.get_qubits())
ro = self.prog.declare('ro', 'BIT', len(qubits))
for i, q in enumerate(qubits):
self.prog.inst(MEASURE(q, ro[i]))
self.prog.wrap_in_numshots_loop(self.shots)
executable = self.qc.compile(self.prog)
bitstring_array = self.qc.run(executable=executable)
self.state = {}
for i, q in enumerate(qubits):
self.state[q] = bitstring_array[:, i]
def test_validate_supported_quil_multiple_measures():
prog = Program(
RESET(),
H(1),
Pragma('DELAY'),
MEASURE(1, None),
MEASURE(1, None)
)
with pytest.raises(ValueError):
validate_supported_quil(prog)
def reset(self, qubit_index: Optional[int] = None) -> "Program":
"""
Reset all qubits or just a specific qubit at qubit_index.
:param qubit_index: The address of the qubit to reset.
If None, reset all qubits.
:returns: The Quil Program with the appropriate reset instruction appended, e.g.
RESET 0
"""
return self.inst(RESET(qubit_index))
def pre_measure(self):
"""Run the QVM"""
# pylint: disable=attribute-defined-outside-init
for e in self.obs_queue:
wires = e.wires
if e.name in [
"PauliX", "PauliY", "PauliZ", "Identity", "Hadamard"
]:
self.pre_rotations(e.name, wires)
elif e.name == "Hermitian":
# For arbitrary Hermitian matrix H, let U be the unitary matrix
# that diagonalises it, and w_i be the eigenvalues.
H = e.parameters[0]
Hkey = tuple(H.flatten().tolist())
if Hkey in self._eigs:
# retrieve eigenvectors
U = self._eigs[Hkey]["eigvec"]
else:
# store the eigenvalues corresponding to H
# in a dictionary, so that they do not need to
# be calculated later
w, U = np.linalg.eigh(H)
self._eigs[Hkey] = {"eigval": w, "eigvec": U}
# Perform a change of basis before measuring by applying U^ to the circuit
self.apply("QubitUnitary", wires, [U.conj().T])
prag = Program(Pragma("INITIAL_REWIRING", ['"PARTIAL"']))
if self.active_reset:
prag += RESET()
self.prog = prag + self.prog
qubits = sorted(self.prog.get_qubits())
ro = self.prog.declare("ro", "BIT", len(qubits))
for i, q in enumerate(qubits):
self.prog.inst(MEASURE(q, ro[i]))
self.prog.wrap_in_numshots_loop(self.shots)
if "pyqvm" in self.qc.name:
bitstring_array = self.qc.run(self.prog)
else:
self.compiled = self.qc.compile(self.prog)
bitstring_array = self.qc.run(executable=self.compiled)
self.state = {}
for i, q in enumerate(qubits):
self.state[q] = bitstring_array[:, i]
def test_biased_coin():
# sample from a 75% heads and 25% tails coin
prog = (
Program().inst(Declare("ro", "BIT"), RX(np.pi / 3, 0)).measure(0, MemoryReference("ro", 0))
)
results = []
qam = PyQVM(n_qubits=1, quantum_simulator_type=ReferenceWavefunctionSimulator)
for _ in range(1000):
qam.execute(prog)
results += [qam.ram["ro"][0]]
qam.execute(Program(RESET()))
coin_bias = sum(results) / 1000
assert np.isclose(coin_bias, 0.25, atol=0.05, rtol=0.05)
def run(q_comp, program, n_shots):
start = time.time()
if use_active_reset:
reset_measure_program = Program(RESET())
program = reset_measure_program + program
# run the program num_shots many times
program.wrap_in_numshots_loop(n_shots)
executable = q_comp.compiler.native_quil_to_executable(program)
res = q_comp.run(executable)
end = time.time()
return res, end - start
def test_reset():
p = Program()
p.reset(0)
p.reset()
assert p.out() == "RESET 0\nRESET\n"
program = Program()
qubit = QubitPlaceholder()
# address_qubits() won't work unless there's a gate besides
# RESET on a QubitPlaceholder, this is just here to make
# addressing work
program += X(qubit)
program += RESET(qubit)
program = address_qubits(program)
assert program.out() == "X 0\nRESET 0\n"
def generate_calibration_experiment(self) -> "Experiment":
"""
Generate another ``Experiment`` object that can be used to calibrate the various multi-qubit
observables involved in this ``Experiment``. This is achieved by preparing the plus-one
(minus-one) eigenstate of each ``out_operator``, and measuring the resulting expectation
value of the same ``out_operator``. Ideally, this would always give +1 (-1), but when
symmetric readout error is present the effect is to scale the resultant expectations by some
constant factor. Determining this scale factor is what we call *readout calibration*, and
then the readout error in subsequent measurements can then be mitigated by simply dividing
by the scale factor.
:return: A new ``Experiment`` that can calibrate the readout error of all the
observables involved in this experiment.
"""
if self.calibration != CalibrationMethod.PLUS_EIGENSTATE:
raise ValueError(
'We currently only support the "plus eigenstate" calibration method.'
)
calibration_settings = []
for settings in self:
assert len(settings) == 1
calibration_settings.append(
ExperimentSetting(
in_state=settings[0].out_operator,
out_operator=settings[0].out_operator,
additional_expectations=settings[0].
additional_expectations,
))
calibration_program = Program()
if self.reset:
calibration_program += RESET()
calibration_program.wrap_in_numshots_loop(self.shots)
if self.symmetrization != SymmetrizationLevel.EXHAUSTIVE:
raise ValueError(
"We currently only support calibration for exhaustive symmetrization"
)
return Experiment(
settings=calibration_settings,
program=calibration_program,
symmetrization=SymmetrizationLevel.EXHAUSTIVE,
calibration=CalibrationMethod.NONE,
)
def test_unsupported_ops():
target = Label("target")
base_prog = Program(Declare('reg1', 'BIT'), Declare('reg2', 'BIT'), H(0),
JumpTarget(target), CNOT(0, 1))
bad_ops = [
RESET(0), WAIT,
Jump(target),
MOVE(MemoryReference('reg1'), MemoryReference('reg2'))
]
assert to_latex(base_prog)
for op in bad_ops:
prog = base_prog + op
with pytest.raises(ValueError):
_ = to_latex(prog)
def two_POVM(theta0, phi0, theta1, theta2) -> Program:
# for the purpose of POVM we choose the most connected qubit (10 in the case) to be the measured one
ancilla = [2]
target = 1
program = Program(RESET())
# create initial state
if theta0 != 0:
program.inst(RY(theta0, target))
if phi0 != 0:
program.inst(RZ(phi0, target))
# 1st AP module
program.inst(POVM_module_1(theta1, theta2, ancilla, target))
return program
def test_is_protoquil():
prog = Program(Declare('ro', 'BIT'), MEASURE(1, MemoryReference("ro", 0)),
H(1), RESET())
validate_protoquil(prog)
assert prog.is_protoquil()
prog = Program(Declare('ro', 'BIT'), H(0), Y(1), CNOT(0, 1)) \
.measure(0, MemoryReference("ro", 0)) \
.if_then(MemoryReference("ro", 0), Program(X(0)), Program())
with pytest.raises(ValueError):
validate_protoquil(prog)
assert not prog.is_protoquil()
prog = Program(Declare('ro', 'BIT'), ClassicalNot(MemoryReference("ro",
0)))
with pytest.raises(ValueError):
validate_protoquil(prog)
assert not prog.is_protoquil()
def apply(self, operations, **kwargs):
"""Run the QVM"""
# pylint: disable=attribute-defined-outside-init
super().apply(operations, **kwargs)
prag = Program(Pragma("INITIAL_REWIRING", ['"PARTIAL"']))
if self.active_reset:
prag += RESET()
self.prog = prag + self.prog
qubits = sorted(self.wiring.values())
ro = self.prog.declare("ro", "BIT", len(qubits))
for i, q in enumerate(qubits):
self.prog.inst(MEASURE(q, ro[i]))
self.prog.wrap_in_numshots_loop(self.shots)
def test_qc_expectation_larger_lattice(forest):
device = NxDevice(nx.complete_graph(4))
qc = QuantumComputer(name='testy!',
qam=QVM(connection=forest),
device=device,
compiler=DummyCompiler())
q0 = 2
q1 = 3
# bell state program
p = Program()
p += RESET()
p += H(q0)
p += CNOT(q0, q1)
p.wrap_in_numshots_loop(10)
# XX, YY, ZZ experiment
sx = ExperimentSetting(in_state=sZ(q0) * sZ(q1),
out_operator=sX(q0) * sX(q1))
sy = ExperimentSetting(in_state=sZ(q0) * sZ(q1),
out_operator=sY(q0) * sY(q1))
sz = ExperimentSetting(in_state=sZ(q0) * sZ(q1),
out_operator=sZ(q0) * sZ(q1))
e = TomographyExperiment(settings=[sx, sy, sz], program=p)
results = qc.experiment(e)
# XX expectation value for bell state |00> + |11> is 1
assert np.isclose(results[0].expectation, 1)
assert np.isclose(results[0].std_err, 0)
assert results[0].total_counts == 40
# YY expectation value for bell state |00> + |11> is -1
assert np.isclose(results[1].expectation, -1)
assert np.isclose(results[1].std_err, 0)
assert results[1].total_counts == 40
# ZZ expectation value for bell state |00> + |11> is 1
assert np.isclose(results[2].expectation, 1)
assert np.isclose(results[2].std_err, 0)
assert results[2].total_counts == 40
def test_qc_calibration_2q(client_configuration: QCSClientConfiguration):
# noise model with 95% symmetrized readout fidelity per qubit
noise_model = asymmetric_ro_model([0, 1], 0.945, 0.955)
qc = get_qc("2q-qvm", client_configuration=client_configuration)
qc.qam.noise_model = noise_model
# bell state program (doesn't matter)
p = Program()
p += RESET()
p += H(0)
p += CNOT(0, 1)
p.wrap_in_numshots_loop(10000)
# ZZ experiment
sz = ExperimentSetting(in_state=_pauli_to_product_state(sZ(0) * sZ(1)), out_operator=sZ(0) * sZ(1))
e = Experiment(settings=[sz], program=p)
results = qc.calibrate(e)
# ZZ expectation should just be (1 - 2 * readout_error_q0) * (1 - 2 * readout_error_q1)
np.isclose(results[0].expectation, 0.81, atol=0.01)
assert results[0].total_counts == 40000
def test_qc_calibration_1q(forest):
# noise model with 95% symmetrized readout fidelity per qubit
noise_model = asymmetric_ro_model([0], 0.945, 0.955)
qc = get_qc("1q-qvm")
qc.qam.noise_model = noise_model
# bell state program (doesn't matter)
p = Program()
p += RESET()
p += H(0)
p += CNOT(0, 1)
p.wrap_in_numshots_loop(10000)
# Z experiment
sz = ExperimentSetting(in_state=sZ(0), out_operator=sZ(0))
e = Experiment(settings=[sz], program=p)
results = qc.calibrate(e)
# Z expectation value should just be 1 - 2 * readout_error
np.isclose(results[0].expectation, 0.9, atol=0.01)
assert results[0].total_counts == 20000
