A number of interesting studies have been done regarding crystals and quantum mechanics:
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The Optical Lattice is an interesting concept that I had been speculating about (though under different terms) for quite some time (though my idea actually involved using it to create a region of space that was forced into energy densities exceeding Planck Energy Density.... which would be absolutely insane amounts of energy). The condensing of matter into low potential areas is a rather interesting side-effect that would probably play a role in any attempts to break Planck Energy (likely what I imagine would happen - the atoms would absorb the excess energy and transmute and/or undergo rapid decay into sprays of particle radiation... or all of that).
Anyway - it has furthered the development of Photonic Crystals - which are crystals designed to influence light in much the same way that semiconductors influence photons.
I suspect that, in the future, direct processing of optical information will be possible - though quantum mechanical phenomena may remain a bit elusive for another 20 or more years... depending upon when a 'breakthrough' is made (and those are hard to predict).
Interestingly, I recall an experiment where electrons in graphene were coaxed to behave as if under an immensely strong magnetic field .... here it is:
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They behave as if under 300 Tesla. Which is stupidly strong.
However... if this phenomena can be extended into a 3d crystalline environment, it could prove useful for the development of Type II superconductors, which require high magnetic field strengths (or electrons to behave as if under them):
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.... and looks like someone beat me to it:
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Though I'm not sure if they are merely proposing a mathematical model, there, or if they actually performed experiments with the material.
I'm jumping way out on a limb, here - but I'd propose this type of thing could be used as a "quantum switch" or "super-switch." By creating a 3d conductor based off of diamond and other doping materials, one could strain the diamond using an applied voltage across one axis to strain the crystalline structure and trigger superconducting behavior across another axis.
Thus, you could have a nearly perfect switch with something next to zero switching loss.
... I think. There might be some complications with the practical implementation of that. It would be more of a highly efficient traic than a transistor, though. But you could rig it as a diac.
The applications and implications for high-power switching are phenomenal. You could switch billions of amps with a component the size of a grain of rice.
Though this has kind of deviated from the original point of your discussion...
