IMO the idea follow the read / write issue on multiple layers that develop now on discs. This could be only the begining of a process .
Advancing in this direction will lead to change the states of the atoms that compound cristals , going even beyond the two state - binary system - actually in use , that is improving a LOT …
A laser with a HIGH frequency ( that is a wavelength of the proper size for the cristal used ) and adequate energy in order to be able to percieve the state of the atom ( but not to modify this state too much - it should not change the particular charaterisic of that state that gives the information ) - this should be the reading process . Different characteristics should have the laser in order to change the state of the atom as it should be to perform the writting. Jumping up from the binary system will dramatically increse the density of the data.
Obviously , handling the single ( better said the sigle pair of ) photon ( s ) will help.
For now , the storage is what keeps computing slow ( in a manner of speaking ) , maybe it will be the fastest part in the future.
I think this COULD BE one way the memory would develop in the future ( not so far I hope ) …
It is only my opinion , I don’t pretend I’m 100% right . Beside , there are technological problems to be solved…
This would mean we ( we as humans ) will master nanotechnology , which today we don’t …