Cloning orthogonal quantum states - circuit?

[Emil_M]

Homework Statement

Hey, the no-cloning theorem states, that arbitrary quantum states cannot be cloned by any circuit.

It is, however, possible to clone orthogonal states.

What would a circuit performing this action look like?

Homework Equations

Relevant equations: I am assuming you all now the most important quantum gates (CNOT, Hadamard, Pauli Matrices etc. )

The Attempt at a Solution

The circuit looks like this:

$|\psi\rangle$ is a general qubit: $|\psi\rangle := a |0\rangle + b|1\rangle$

I am assuming a CNOT gate has to be applied at some point, followed by the application of further gates to the lower qubit. I am, however, not sure how the coefficients can be "transferred" to the lower qubit.Thank you!

 

[DrClaude]

What state do you get after the application of the CNOT gate?