Quantum Computation, Lecture 22, QEC, Part 3, Bit, phase flip error correction circuits, Mar 10, '22

XOR as parity check operation between two Boolean variables; using parity check to construct the error diagnosis and recovery circuit for (single) bit flip error in 3 qubit repetition code.

"Non-destructive" operator measurement: circuits for measuring the results of acting with a given unitary (which have eigenvalue ±1) on a given quantum state and obtaining the resulting eigenvalue, without collapsing the given state; related circuit identities.

Circuit for 3-qubit, (single bit) phase flip error diagnosis and recovery.