PHYSICS · Subjective · Fermi University Physics · Quantum Information & Technology · Open quantum systems, decoherence and error correction · Open quantum systems, decoherence and error correction
Quantum Information and Technology, Ch The stabilizer formalism
Problem
Three qubits start in ∣000⟩, stabilized by {Z1,Z2,Z3}. The following circuit is applied, in this order: a Hadamard H on qubit 2; a CNOT with qubit 2 as control and qubit 1 as target; a CNOT with qubit 2 as control and qubit 3 as target. Use the conjugation rules H:X↔Z (on the qubit it acts on) and, for CNOTc→t: Xc→XcXt, Zt→ZcZt, with Xt and Zc unchanged, to track the stabilizer generators through the circuit step by step. Give the three generators of the final state and identify that state.