def detector_tomography_circuits_pymali(qubit_indices, probe_kets):
"""
Analogical method_name of the circuits preparing method_name utilizing pymali general tensor calculator.
"""
qubit_indices = sorted(
qubit_indices
) # Sort to ensure, that results can easily be interpreted.
tomography_circuits = []
unitaries = [
povmtools.get_unitary_change_ket_qubit(ket) for ket in probe_kets
]
# create nice list with proper ordering of circuits. In first step, last qubit in list qubit_indices is iterated
# while all the other are fixed. See function description for details.
gtc = GeneralTensorCalculator.GeneralTensorCalculator(
gtc_tensor_calculating_function)
unitaries_lists_for_tensor_calculator = [
unitaries.copy() for i in range(len(qubit_indices))
]
list_of_unitaries_sets = gtc.calculate_tensor_to_increasing_list(
unitaries_lists_for_tensor_calculator)
qrs = max(qubit_indices) + 1
# inner loop goes through all circuits in QDT experiments and prepares them
for unitaries_set in list_of_unitaries_sets:
qreg = QuantumRegister(qrs)
creg = ClassicalRegister(len(qubit_indices))
circuit = QuantumCircuit(qreg, creg)
circuit.barrier() # To prevent compiler from making changes.
for j in range(len(unitaries_set)):
current_angles = povmtools.get_su2_parametrizing_angles(
unitaries_set[j])
# TODO TR: I believe there may be more "special" cases.
# If so, then this should be placed in other method_name
# or in get_su2_ ... method_name.
if current_angles[0] == 'id':
circuit.i(qreg[qubit_indices[j]])
continue
if current_angles[0] == 'x':
circuit.x(qreg[qubit_indices[j]])
continue
# implement unitary
circuit.u3(current_angles[0], current_angles[1], current_angles[2],
qreg[qubit_indices[j]])
# Add measurements
for i in range(len(qubit_indices)):
circuit.measure(qreg[qubit_indices[i]], creg[i])
tomography_circuits.append(circuit)
return tomography_circuits
def detector_tomography_circuits_rigetti(qubit_indices,
probe_kets,
number_of_repetitions=1,
shots=8192,
qrs=None):
"""From list of probe kets and qubit data return quantum circuits which will be implemented to perform
Quantum Detector Tomography (QDT).
:param probe_kets: (list of numpy arrays) the list of ket representations of qubit pure quantum states which are to
be used in QDT. For multi-qubit QDT, the combinations of tensor products of name_appendix will be taken.
:param qubit_indices: (list of ints) labels of qubits for QDT
:param number_of_repetitions: (int) parameter specifying how many copies of whole QDT experiment should be created
(for larger statistics collection or comparision of results)
:return: (list of QuantumCircuit objects) of length len(probe_states)**(number_of_qubits)
"""
import pyquil as pyq
qubit_indices = sorted(
qubit_indices
) # Sort to ensure, that results can easily be interpreted.
unitaries = [
povmtools.get_unitary_change_ket_qubit(ket) for ket in probe_kets
]
# create nice list with proper ordering of circuits. In first step, last qubit in list qubit_indices is iterated
# while all the other are fixed. See function description for details.
indices_for_circuits = get_list_of_lists_indices_qdt(
qubit_indices, len(unitaries))
if qrs is None:
qrs = max(qubit_indices) + 1
tomography_circuits = []
# inner loop goes through all circuits in QDT experiments and prepares them
for index_for_set in range(len(indices_for_circuits)):
# index of set of qubits+unitaries for current step
current_set = indices_for_circuits[index_for_set]
# create quantum register
# qreg = QuantumRegister(quantum_register_size)
# creg = ClassicalRegister(len(qubit_indices))
# create quantum circuit with nice names
set_string = ''.join(['u' + str(st) for st in current_set[0]])
qubits_string = ''.join(['q' + str(st) for st in qubit_indices])
#
# circuit = QuantumCircuit(qreg, creg,
# name="QDT-" + qubits_string + "-id-" + set_string + '-no-' + str(number))
program = pyq.Program()
ro = program.declare('ro', memory_type='BIT', memory_size=qrs)
# get barrier to prevent compiler from making changes
# circuit.barrier()
for qubit_unitary_pair_index in range(len(current_set)):
# take qubit+unitary pair
pair_now = current_set[qubit_unitary_pair_index]
# take index of qubit and index of unitary
q_now_index, u_now_index = pair_now[0], pair_now[1]
# make sure that chosen quantum state is not one of the states in computational basis
# TODO: this might not be necessary anymore, it's an old code, I had some problems long time ago with
# those guys because qiskit compiler went crazy if I defined identity or x gate using u3 unitary.
if u_now_index == 0:
program += pyq.gates.I(q_now_index)
elif u_now_index == 1:
program += pyq.gates.X(q_now_index)
elif u_now_index == 2:
program += pyq.gates.H(q_now_index)
elif u_now_index == 3:
program += pyq.gates.X(q_now_index)
program += pyq.gates.H(q_now_index)
elif u_now_index == 4:
program += pyq.gates.H(q_now_index)
program += pyq.gates.S(q_now_index)
elif u_now_index == 5:
program += pyq.gates.X(q_now_index)
program += pyq.gates.H(q_now_index)
program += pyq.gates.S(q_now_index)
# Add measurements
for i in range(len(qubit_indices)):
program += pyq.gates.MEASURE(qubit_indices[i], ro[i])
program.wrap_in_numshots_loop(shots)
tomography_circuits.append(program)
return tomography_circuits
def detector_tomography_circuits(qubit_indices,
probe_kets,
number_of_repetitions=1,
qrs=None):
"""From list of probe kets and qubit data return quantum circuits which will be implemented to perform
Quantum Detector Tomography (QDT).
:param probe_kets: (list of numpy arrays) the list of ket representations of qubit pure quantum states which are to
be used in QDT. For multi-qubit QDT, the combinations of tensor products of name_appendix will be taken.
:param qubit_indices: (list of ints) labels of qubits for QDT
:param number_of_repetitions: (int) parameter specifying how many copies of whole QDT experiment should be created
(for larger statistics collection or comparision of results)
:return: (list of QuantumCircuit objects) of length len(probe_states)**(number_of_qubits)
"""
qubit_indices = sorted(
qubit_indices
) # Sort to ensure, that results can easily be interpreted.
tomography_circuits = []
unitaries = [
povmtools.get_unitary_change_ket_qubit(ket) for ket in probe_kets
]
# create nice list with proper ordering of circuits. In first step, last qubit in list qubit_indices is iterated
# while all the other are fixed. See function description for details.
indices_for_circuits = get_list_of_lists_indices_qdt(
qubit_indices, len(unitaries))
if qrs is None:
qrs = max(qubit_indices) + 1
# outer loop is for copies of QDT experiment
for number in range(number_of_repetitions):
# inner loop goes through all circuits in QDT experiments and prepares them
for index_for_set in range(len(indices_for_circuits)):
# index of set of qubits+unitaries for current step
current_set = indices_for_circuits[index_for_set]
# create quantum register
qreg = QuantumRegister(qrs)
creg = ClassicalRegister(len(qubit_indices))
# create quantum circuit with nice names
set_string = ''.join(['u' + str(st) for st in current_set[0]])
qubits_string = ''.join(['q' + str(st) for st in qubit_indices])
circuit = QuantumCircuit(qreg,
creg,
name="QDT-" + qubits_string + "-id-" +
set_string + '-no-' + str(number))
# get barrier to prevent compiler from making changes
circuit.barrier()
for qubit_unitary_pair_index in range(len(current_set)):
# take qubit+unitary pair
pair_now = current_set[qubit_unitary_pair_index]
# take index of qubit and index of unitary
q_now_index, u_now_index = pair_now[0], pair_now[1]
# make sure that chosen quantum state is not one of the states in computational basis
# TODO: this might not be necessary anymore, it's an old code, I had some problems long time ago with
# those guys because qiskit compiler went crazy if I defined identity or x gate using u3 unitary.
if povmtools.check_if_projector_is_in_computational_basis(
povmtools.get_density_matrix(probe_kets[u_now_index])):
if povmtools.get_density_matrix(
probe_kets[u_now_index])[0][0] == 1:
circuit.i(qreg[q_now_index])
elif povmtools.get_density_matrix(
probe_kets[u_now_index])[1][1] == 1:
circuit.x(qreg[q_now_index])
else:
raise ValueError('error')
else:
# get angles for single-qubit state change unitary
current_angles = povmtools.get_su2_parametrizing_angles(
unitaries[u_now_index])
# implement unitary
circuit.u3(current_angles[0], current_angles[1],
current_angles[2], qreg[q_now_index])
# Add measurements
for i in range(len(qubit_indices)):
circuit.measure(qreg[qubit_indices[i]], creg[i])
tomography_circuits.append(circuit)
return tomography_circuits