Quantum Computing, Fault Tolerance, Error Correction, Logical Qubits.
qubits. From another perspective: There are d² data qubits So for d = 5, 5² = 25 And There are (d + 1) / 2 * (d — 1) syndrome measurement qubits. So for d = 5, that’s 6 / 2 * 4 = 3 * 4 = 12 syndrome measurement qubits. And There are d * (d — 1) flag qubits. So for d = 5, that’s 5 * 4 = 20 flag