def test_string2nodes(self):
"""Test string2nodes with different logical values."""
code = RepetitionCode(3, 2)
dec = GraphDecoder(code)
s0 = '0 0 01 00 01'
s1 = '1 1 01 00 01'
self.assertTrue(
dec._string2nodes(s0,
logical='0') == dec._string2nodes(s1,
logical='1'),
'Error: Incorrect nodes from results string')
def test_string2nodes(self):
"""Test string2nodes with different logical values."""
code = RepetitionCode(3, 2)
dec = GraphDecoder(code)
s0 = "0 0 01 00 01"
s1 = "1 1 01 00 01"
self.assertTrue(
dec._string2nodes(s0,
logical="0") == dec._string2nodes(s1,
logical="1"),
"Error: Incorrect nodes from results string",
)
def single_error_test(self, code):
"""
Insert all possible single qubit errors into the given code,
and check that each creates a pair of syndrome nodes.
"""
decoder = GraphDecoder(code)
for logical in ["0", "1"]:
qc = code.circuit[logical]
blank_qc = QuantumCircuit()
for qreg in qc.qregs:
blank_qc.add_register(qreg)
for creg in qc.cregs:
blank_qc.add_register(creg)
error_circuit = {}
circuit_name = {}
depth = len(qc)
for j in range(depth):
qubits = qc.data[j][1]
for qubit in qubits:
for error in ["x", "y", "z"]:
temp_qc = blank_qc.copy()
temp_qc.name = str((j, qubit, error))
temp_qc.data = qc.data[0:j]
getattr(temp_qc, error)(qubit)
temp_qc.data += qc.data[j:depth + 1]
circuit_name[(j, qubit, error)] = temp_qc.name
error_circuit[temp_qc.name] = temp_qc
simulator = Aer.get_backend("aer_simulator")
job = execute(list(error_circuit.values()), simulator)
for j in range(depth):
qubits = qc.data[j][1]
for qubit in qubits:
for error in ["x", "y", "z"]:
raw_results = {}
raw_results[logical] = job.result().get_counts(
str((j, qubit, error)))
results = code.process_results(raw_results)[logical]
for string in results:
nodes = decoder._string2nodes(string,
logical=logical)
self.assertIn(
len(nodes),
[0, 2],
"Error of type " + error + " on qubit " +
str(qubit) + " at depth " + str(j) +
" creates " + str(len(nodes)) +
" nodes in syndrome graph, instead of 2.",
)