[diontron]

semiconductors don't "use" quantum physics, quantum physics just tries to explain how they work. semiconductors still exist without requiring quantum physicists to come in and try and steal credit for something they had no influence on whatsoever.

[pmontra]

They used to but manufacturers are starting to have to deal with quantum effects lately https://semiengineering.com/quantum-effects-at-7-5nm/

[baja_blast]

How is explaining/figuring out how quantum physics effects semiconductors "stealing credit"? Learning about how quantum tunneling effects impact super small transistors is extremely useful since chip designers can use this info to design chips that mitigate this effect as we scale down.

Also in the material sciences metamaterials have special properties precisely because of how the molecular structure manipulates quantum forces. https://www.nature.com/articles/s41467-019-09939-8

[danbruc]

Nothing in the universe »uses« quantum physics. Or classical physics. Or any physics. Or any science. Or anything made by man. Or aliens. All a waste of time and resources.

[dekhn]

This is sort of a profoundly different way of looking at it. The creation of the first semiconductors was closely tied to the development of quantum theory around electrons in metal. Bell labs hired up Shockley, Bardeen and a bunch of other solid state physicists (when it started to become obvious that the US needed to build computing devices that were faster and more rugged than vacuum tubes) and it was their knowledge of quantum physics that enabled them to solve key problems in the development of the transistor.

QM is still the best theory for semiconductors and a lot of semiconductor improvement happens by applying quantum physics.

The important part to recognize is that this is a part of QM that doesn't involve entanglement or wave function collapse, but definitely relies heavily on quantum tunnelling. All of this is well documented by the primary literature in the field.

[mikewarot]

It may be that is how it started, but I'll never forget the day my Advanced Chemistry teacher at Rose-Hulman used standard chemistry (I think it was the Nerst equation, 40 years ago!) to explain how a diode works.

Then he continued and explained how a junction transistor worked with the same equations!

No QM required.

[dekhn]

The nernst equation is https://en.wikipedia.org/wiki/Nernst_equation (redox). THere's also https://en.wikipedia.org/wiki/Nernst%E2%80%93Planck_equation which also isn't exactly for diode modelling.

I'm sure you can find classical equations that model some aspects of p-n junctions but you're ultimately going to see that p-n junction physics is literally quantum physics of tunneling electrons in atomic solids.

[mikewarot]

It's not tunneling, it's conduction. There are liquid electrolytic rectifiers, they suck, but they exist.

[dekhn]

Oh, I see what you're saying now. Your teacher showed you the equations explaining a classical (pre-semiconductor) diode, then showed those equations predict some aspects of semiconductor diodes.

Yeah, that doesn't mean that diodes don't work in a fundamentally quantum way. There are a number of details about diodes (for example, the emitted frequency of light in an LED) that are very specifically due to quantum energy transitions of electrons in outer shells. It doesn't get any more quantum physics than that.

[mikewarot]

This was the equations for a doped semiconducting device, not a vacuum tube. All the equations we had previously been using to describe buffered solutions, etc. also happened to work perfectly well for semiconductors.

LEDs weren't discussed that day.

[klyrs]

Now do Josephson Junctions. https://en.wikipedia.org/wiki/Josephson_voltage_standard

[ben_w]

Indeed, or superfluids, Fermi-Dirac and Bose-Einstein condensates, quantum computers, lasers, quantum dot displays, quantum key distribution, MRI scanners, that trick with 3 polarising filters letting though more light than just 2, antimatter, and electron microscopes.

Oh, and Casimir cavities.

[evanb]

Not for nothing but Shockley, Bardeen, and Brattain were physicists awarded a Nobel "for their researches on semiconductors and their discovery of the transistor effect". Bardeen also won a separate Nobel for a theory of superconductivity. Claiming they're not quantum physicists or had no influence on semiconductors is misinformed.