Where my explanation of Grover’s algorithm failed
Addressing some viewer questions from the most recent video
In the most recent video about quantum computing, in response to the section on Grover’s algorithm, I saw many comments expressing a very similar point of confusion. I made a follow-up video, which I hope may help clarify some of the issues, and which also doubles as an excuse to talk a bit more about the central role of linearity in quantum computing.
Hello, and thank you.
What wasn't clear for me, and also made me think that it seems you have to know the answer during the process, was the symmetry in reference to the tilted axis. What's that operation ?
I understand that you can change the sign of the axis representing the correct answer. But obviously , if you repeat this step , there is no convergence and you just flip the x axis indefinitely.
So between each "sign change of the right answer vector " step , you make a rotation /symmetry of the current vector state , following a plane of symetry that seems to be known only by the "correct answer" but affecting all the vector components (it is not anymore only the correct answer that change sign, but all vector that change their value ).
How does this step can occur ? I have intuition that it may just be normalization , but I cannot understand.
It probably would have helped to put a second 2D graph next to it, where the vertical axis was a random incorrect answer.