$ logical qubit $ A4. Consider the error-correction circuit shown on the right. Determine the input state ) = (al + 6X1 + X2 + dX3)(a|000) + B|111)00) describing the logical qubit with single-qubit spin-flip errors, the state after the syndrome diagnosis and the state after the recovery operation. ancilla qubits 10) - syndrome diagnosis recovery operations $ logical qubit $ A4. Consider the error-correction circuit shown on the right. Determine the input state ) = (al + 6X1 + X2 + dX3)(a|000) + B|111)00) describing the logical qubit with single-qubit spin-flip errors, the state after the syndrome diagnosis and the state after the recovery operation. ancilla qubits 10) - syndrome diagnosis recovery operations