Amplitude Amplification2 QubitsQuadratic Speedup O(√N) vs Classical O(N)6 Learning Stages
Grover's Search Algorithm
Unstructured quantum search through phase oracle marking and amplitude amplification.
Stage 6 Required
Plain-Language Intuition
Imagine searching for a specific face in a crowd of N people.
Classically, you must check each person one by one (on average N/2 checks, and in the worst case N checks).
Grover's Quantum Search works like an audio equalizer:
1. First, you put all items in equal volume (superposition).
2. The Oracle turns the phase of the target face upside down (inverts its sign to negative).
3. The Diffusion Operator flips all amplitudes around their average value. Since the target face was negative, this pulls its volume WAY UP to nearly 100% while canceling out all the wrong faces!