> I don't know if we'll see practical atomic storage or if more than one bit per atom is physically possible, but in theory there's enough space in an atom to hold millions of bits.
I think he means that physical space could accommodate such number of bits before a black hole forms, not that we can tame an atom specifically to hold that information.
I thought he meant that you could encode more than one of two states. For a very base analogy, instead of just - and | representing 1 and 0, you could have - \ | / representing 00, 01, 10, 11, etc. Wifi does something similar with signal phase.
While I could (and do) definitely have fun speculating that more than two states might be possible to represent - I can imagine a bunch of armchair physics possibilities - I didn't mean to suggest anything specific. The Bekenstein bound is only an idea, there's no known physical way to get even close.
Maybe ionizing states, or bonds using multiple kinds of atoms, or use of radioactive elements, maybe something like that could be used to represent multiple states... I'm sure IBM & other labs are pushing to find out as fast as funding permits.
I can imagine a bunch of armchair physics possibilities
normal caveats (not a physicist, chemist, lawyer, etc)
Since atoms are made of multiple components, if you can modify and measure those components individually, then it's at least theoretically possible to encode more than two states per atom. All of the following assumes you would want to keep the same atomic number for the duration, obviously if you don't care what type of atom you're storing then there would obviously be many more than two states.
If it was possible set and count how many neutrons an particular atom has (aka which isotope), then it would be possible to encode more. Even Hydrogen has three isotopes, and Xenon has nine stable isotopes (and many more unstable). Same for number of electrons (aka ions).
If there are more properties that could be manipulated for each of those individual components, then it would be possible to have even more states. (ex: electron spin).
For example, with a hydrogen atom and it's 3 isotopes, it's theoretically possible to encode 4 states (2^2, half-nibble, crumb)
What will you encode the bits with?