Chapter 4

Question 1

Describe the quantum teleportation circuit

Answer 1

• Initialised over three qubits with the middle being shared between Alice and Bob
• The top qubit is a general state and the bottom two qubits are the Bell state:

1. CNOT (control on qubit 3, target on qubit 2
2. Hadamard on qubit 3
3. Measure qubits 3 and 2
4. Send classical information to qubit 1 via control X and Z gates

Question 2

Describe the superdense coding circuit

Answer 2

• Iniitalised over Bell state and two classica bits a, b

1. b sends classical info which controls Z gate on qubit 2
2. a sends classical info which controls X gate on qubit 2
3. CNOT (control on qubit 2, target on qubit 1)
4. Hadamard on qubit 2
5. Measurement