Figure 6

The figure illustrates that Alice who is only capable of performing \(R_{Z}(\frac{\pi}{4})\) can achieve the operation \(HR_{Z}(\frac{\pi}{4})\) with the help of Bob. The quantum operations that Alice performs in Protocol 2 are circled by the dotted lines. Alice performs \(R_{Z}(\frac{\pi}{4})\) on the ancilla sent by Bob and then sends it back to Bob. After that, Bob performs X basis measurement on the ancilla and informs Alice of the measurement result through the classical channel