Confusion with first problem of I.7 I.7 Universal gate sets

Codebook
1

hi,

i’m a bit confused about the 1.7.1 problem. i find the values of the euler angles that are necessary to get the hadamard gate from multiplying Rx and Rz but the codebook keep telling me that my output is not correct. not sure i know how to proceed.

any help will be greatly appreciated.

best,
-o-

2

I remember spending a lot of time myself on this question. I might be able to help if you’re willing to share some details of your answer and steps. One of my mistakes was forgetting to multiply the angle I got by 2, since the matrices uses angle/2 but the functions take angle as input.

3

Hi @ogopogo,

Notice that you’re multiplying RZ, RX and again RZ. The issue may be with what @Kamal_Mohamed mentioned or it may also be that you’re not multiplying by RZ again. I hope this helps you!

4

Hi Kamal and Catalina,

Thank you for your feedback! I was making the mistake of thinking about the angles without the factor of two. that took care of the problem.

best,
-a-

2 Likes
5

Glad to see your question answered :smiley: !

1 Like
6

i also gt the wrigth ateta angle but i am really stuck at finding omega and phi. is there some hint?
Thank you:
Horacio

7

Hi @ogopogo @ogopogo @Kamal_Mohamed
i also get the wright teta angle but i am really stuck at finding omega and phi. is there some hint?
Thank you:
Horacio

8

Hi @Horacio.

You will need to do the matrix multiplication for RZ(omega)*RX(theta)*RZ(theta) and compare it with the matrix for H. Now, consider that the exercise says “up to a global phase”. This means that you should multiply your RZ RX RZ side of the equation by e^{i\gamma} where \gamma can be any value so you have to solve for it too.

Hopefully this helps you solve this question!