"It even exists in the simple light switch. The switch would not work if electrons could not quantum tunnel through the layer of oxidation on the metal contact surfaces."
Is there something specific about oxidized metal that electrons need quantum tunneling to move through them? Why can't we just assume its normal conductivity?
Aluminum is extremely reactive, and the classic method of liberating this energy is through thermite reactions. Without the oxidation layer on aluminum, it would be an extremely hazardous substance.
"Breaking bad" covered this with an etch-a-sketch. Sometimes chemistry can be surprising.
That's neat but I don't really follow. Why isn't the oxidation layer just a higher impedance material? Why is quantum tunneling required to explain a light switch?
The one that I remember foremost is tunneling to (dis)charge the floating gates on flash memory transistors, but that just scratches the surface.
"Flash memory chips found in USB drives use quantum tunneling to erase their memory cells."
https://en.m.wikipedia.org/wiki/Applications_of_quantum_mech...
This I did not know:
"It even exists in the simple light switch. The switch would not work if electrons could not quantum tunnel through the layer of oxidation on the metal contact surfaces."