[HN Gopher] Quantum Weirdness in New Metals Bends the Rules of P...
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Quantum Weirdness in New Metals Bends the Rules of Physics
Author : LinuxBender
Score : 22 points
Date : 2024-03-19 16:09 UTC (6 hours ago)
(HTM) web link (www.scientificamerican.com)
(TXT) w3m dump (www.scientificamerican.com)
| rolph wrote:
| > bends OUR rules of physics. >THE rules of physics are still up
| for discovery.
| sunshine_reggae wrote:
| Exactly. Too many people still act as if everything had already
| been discovered, was known and fully understood.
|
| And as a result, new findings or solutions are often ignored,
| instead of used for the benefit of all.
| digging wrote:
| This seems like a non-sequitur. I don't see that there's any
| way to interpret the title that doesn't imply there are new
| discoveries in the laws of physics.
| kingofthecob wrote:
| Yes, THE laws of physics pretty clearly refers to OUR laws
| of physics in this context. There is no other law. There
| will never be any absolute truth to be considered THE law
| of physics, only ever the models we contrive.
| kbenson wrote:
| THE rules of physics _are_ OUR approximation of how we
| understand the physical reality we live in. They are a human
| invention to describe a existing system, and thus the "our" is
| implied.
| jobead wrote:
| https://archive.is/Lgaz2
| z2h-a6n wrote:
| Minor but perhaps significant nitpick: the title of the article
| is "Quantum Weirdness in New _Strange_ Metals Bends the Rules of
| Physics ", and in this case "Strange Metal" is a technical term.
| If the title is to be edited for length or clickbait-
| minimization, I would recommend removing the word "New", since
| the start of this story is at least ~38 years old, possibly
| older.
| prox wrote:
| Also it's backwards titled, since it is bending our
| _understanding_ of the rules of Physics.
| peter_d_sherman wrote:
| >These "strange metals" have resistivity at low temperatures that
| is linearly proportional to temperature--that is,
|
| _their resistivity varies with the actual temperature rather
| than with the square of the temperature._ "
|
| Interesting...
|
| That could be worth further exploration!
| chasil wrote:
| And I think it implies that strange metals are _not_ Landau
| Fermi liquids:
|
| >Almost 70 years ago Russian physicist Lev Landau and his
| collaborators introduced an incredibly successful conjecture,
| now known as Landau Fermi liquid theory, to try to understand
| electron interactions within metals.
|
| >Physicists have discovered an entire zoo of quasiparticles in
| solid materials with names such as phonons, magnons, spinons,
| holons and plasmons.
|
| >By thinking of the collective actions of electrons as
| quasiparticles, physicists have made testable predictions that
| have been verified time and again in experiments on metals such
| as gold, silver, copper and aluminum.
|
| >In recent years physicists have found a dozen or more
| materials that are clearly metals, in the sense that their
| electrical resistivity decreases with decreasing temperature,
| but that are not Fermi liquids. These "strange metals" have
| resistivity at low temperatures that is linearly proportional
| to temperature--that is, their resistivity varies with the
| actual temperature rather than with the square of the
| temperature.
|
| >Scientists have observed superconductivity emerging in
| multiple families of strange metals at relatively high
| temperatures.
| z2h-a6n wrote:
| That is the common interpretation in the field, and in fact
| the phrases "strange metal" and "non-Fermi-liquid" are used
| somewhat interchangeably.
|
| I'd point out that there is another interpretation of
| resistivity that is linear in temperature, namely that the
| basic physics of electron transport [1] is the same as a
| standard metal, where the scattering rate (proportional to
| resistivity) is proportional to temperature squared. The
| difference from normal metals is attributed to the linear
| increase in the carrier concentration (e.g. density of free
| electrons) with temperature. Since the carrier concentration
| (in the simple model) is inversely proportional to
| resistivity, this partially cancels the T^2 dependence of the
| scattering rate and produces T-linear resistivity. This is
| not (yet?) widely accepted in the literature, and I doubt it
| can explain all T-linear resistivity, but I think there's
| fairly strong evidence to believe it could explain some
| instances of T-linear resistivity, e.g. in the cuprates [2].
| (n.b. I'm academically associated with some of the proponents
| of this idea, though I'm personally somewhat agnostic on the
| matter.)
|
| [1]: https://en.wikipedia.org/wiki/Drude_model [2]:
| https://iopscience.iop.org/article/10.1088/1367-2630/ab4d0f
| z2h-a6n wrote:
| The understanding of strange metals, and more broadly, systems
| (i.e. materials) where strong (often quantum) interactions are
| important is one of the main general research areas of modern
| physics. This is motivated partly by the interest in
| understanding the fundamental physics involved, and partly
| because these strongly-interacting systems often have other
| interesting properties such as high-temperature
| supeconductivity, or various magnetic properties that may be
| useful for quantum computing. It's a large and active area of
| research.
| fuzzfactor wrote:
| Maybe the rules of physics need to have a measure of
| "ductility" all their own.
|
| So they don't get really bent out of shape ;)
|
| I know what I would be doing with an alloy like that.
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