Measure Ball

[This is my entry to https://equs.org/events/games, it came runner up! :D]

Measure Ball uses the mechanics of the quantum system known as the Rabi problem, as well as quantum measurement, and turns them into a challenge.

Use radiation to position the spin of a two level atom so that it’s measured to be in the direction highlighted. You must vary the phase of the radiation to ensure the spin arrow (Bloch vector) takes a path to the right location. When the spin is measured along an axis, it will collapse to either be in the same direction or opposite direction to that axis. The further along it points in the direction of the axis, the more likely it will be measured in that direction. If the spin is measured in the opposite direction to what is stated 3 times, you lose.

I hope that this will give players, that are students of QM in particular, some intuition into how this system works, and what each part actually physically does, which might get lost when solving the system analytically, especially without drawing or animating the results on a Bloch Sphere. The description above probably sounds confusing to people who haven’t seen this stuff before, but that’s the point – it might be easier to learn about the Rabi problem by first playing around and experimenting with it in the game, rather than going through formal theory.