Classics gone quantum : Finding Nemo
Challenge: Find Nemo in the ocean
Grover’s algorithm is designed to search an unstructured database. It’s the perfect tool to find Nemo among countless fish in the ocean.
To do this, we first need to define the characteristics of the correct solution to our problem: a small orange fish with a tiny fin and white-and-black stripes… This first step is called the oracle. The oracle changes the phase of the quantum states that match the correct solution. The “oracle box” represents all the quantum gates required to flip the phase—in this case, that of Nemo. We illustrate the phase flip by changing the little fish’s color and orientation.
By then applying the diffuser, we boost our chances of finding Nemo.
Scientific note
The oracle and diffuser can be applied multiple times to further increase the chances of obtaining a valid solution to the problem.
Movie note
Nemo is found at 42 Wallaby Way, Sydney—and 42 corresponds to the binary number 101010.
To learn more about the different quantum logical gates, watch this video.