We’re rewarding the question askers & reputations are being recalculated! Read more.

Questions tagged [phase-kickback]

For questions about phase kick-back. For a detailed description of the mechanism, go through https://quantumcomputing.stackexchange.com/questions/2565 and the answers therein.

Filter by
Sorted by
Tagged with
3
votes
1answer
21 views

Obtaining phases of all basis states

I’m wondering that is there a way to separate phases of basis states from the magnitudes (namely putting phases on some new basis states with the same probability magnitude) if the exact values of ...
4
votes
2answers
74 views

Is the $|-\rangle$ state the only one that can do the trick for Grover's algorithm?

$\newcommand{\qr}[1]{|#1\rangle}$Grover algorithm's input is a superposition, representing the haystack, and the Bell state $\qr{-}$. The $\qr{-}$ seems utterly important: when I replaced $\qr{-}$ by,...
7
votes
2answers
112 views

Equivalent unitary transformations

Suppose $x \in \{0,1\}^n$. The standard way to make a query is with an oracle $O_x$ that given an input $|i,b \rangle $ returns $|i,b \oplus x_i \rangle$. Via the phase kick-back trick, this can be ...
7
votes
2answers
159 views

Who discovered the phase kickback trick?

Was it David Deutsch? Can you say who was the first paper to mention the phase kickback trick?
11
votes
3answers
1k views

Why does the “Phase Kickback” mechanism work in the Quantum phase estimation algorithm?

I've probably read the chapter The quantum Fourier transform and its applications from Nielsen and Chuang (10 th anniversary edition) a couple of times before and this took this thing for granted, but ...