Imaging a system of two qubits which at a given step of evolution is in the state
- $|q_{1}(0)> = |0> + e^{-i\phi_{1}}|1>$$|q_{1}(0)\rangle = |0\rangle + e^{-i\phi_{1}}|1\rangle$,
- $|q_{2}(0)> = |0> + e^{-i\phi_{2}}|1>$$|q_{2}(0)\rangle = |0\rangle + e^{-i\phi_{2}}|1\rangle$,
is there a simple two qubit quantum circuit of n$n$ gates (CNOT, Hadamard and single-qubit rotations) that produces the output
- $|q_{1}(n)> = |0> + e^{-i\left(\phi_{1}+\phi_{2}\right)}|1>$$|q_{1}(n)\rangle = |0\rangle + e^{-i\left(\phi_{1}+\phi_{2}\right)}|1\rangle$
- $|q_{2}(n)> = |0> + e^{-i\phi_{2}}|1>$$|q_{2}(n)\rangle = |0\rangle + e^{-i\phi_{2}}|1\rangle$
from the input above?