I am a new beginner in quantum algorithms. Recently, I was trying to learn the quantum minimum finding algorithm appeared in here. I am struggling to fully understand the operations in the algorithm.
- What does the "Mark every item $j$ for which $T[j]<T[y]$" really mean? Does it mean we need to define a conditional phase flip oracle whose condition is to check whether $T[j]<T[y]$?
- Can such a conditional phase flip oracle be explicitly constructed?
- "Apply the quantum exponential searching algorithm of 2" is unclear to me. What type of quantum exponential searching algorithm should we use in [2]? Since we do not know how many items in a list satisfying the condition $T[j]<T[y]$, should we use the algorithm for unknown number of solutions? Which steps should we use in the searching algorithm?
- For step 2(b), "Apply the quantum exponential searching algorithm". Does it mean that one should apply the whole process of searching, e.g., the Grover algorithm, which applies the Grover operator $G$ several times, or use the amplitude amplification once?
Basically, I want to have a clear picture of the whole algorithmic process and make sure to understand how each step works.