Every so often, along comes a story which, like [Fox Mulder] with his unexplained phenomena, we want to believe. EM drives and cold fusion for example would be the coolest of the cool if they worke…
If it’s been proven that the levitation isn’t a result of the Meissner effect, I don’t see why there is any reason to believe that material is in a superconducting state.
Not at room temperature. According to the Wikipedia page, one team in China has a preliminary report stating they got superconductivity (or at least 10^-5Ω) at 110°K, so maybe that temperature can be increased somehow?
The only proof of superconductivity is from simulations done by Berkely National Labs, but only when the copper atom is in a higher energy than normal position in the crystal lattice, making changes of it doing so in the current production technique small. For this reason I’m still holding out hope that it’s just the synthesis process that needs refining, or if it really isn’t a room temp superconductor, will at least lead to a proper room temp superconductor in the near future
Mind you, the DFT calculation from the Griffin paper is not a proof of LK 99 being a superconductor in any way. What it showed is the (potential) formation of flat bands near the Fermi surface. Band dispersion is associated with the kinetic energy of the electrons, so materials with flat band (and therefore electrons with suppressed kinetic energy) at the Fermi surface are more susceptible to interaction effect (and strong interaction causes all sorts of nonintuitive quantum effects). I’m not a DFT expert in any sense, but from what I’ve heard, it is quite easy to “tune” your model to produce narrow (the limit of which being flat) bands from substitutions (e.g. the Cu substitution in this case) and such, which don’t necessarily lead to superconductivity.
So I’ll take the DFT papers (there are quite a few now) as saying, “hey you want some flat band? Here’s some. We’ve done our part. Now some other theorist, do your magic and conjure up some superconductivity”. It’s a cog in the full picture, if there is a full picture
Has anyone been able to prove superconductivity?
If it’s been proven that the levitation isn’t a result of the Meissner effect, I don’t see why there is any reason to believe that material is in a superconducting state.
Not at room temperature. According to the Wikipedia page, one team in China has a preliminary report stating they got superconductivity (or at least 10^-5Ω) at 110°K, so maybe that temperature can be increased somehow?
It would be worse than cuprate superconductors which need 130K.
The only proof of superconductivity is from simulations done by Berkely National Labs, but only when the copper atom is in a higher energy than normal position in the crystal lattice, making changes of it doing so in the current production technique small. For this reason I’m still holding out hope that it’s just the synthesis process that needs refining, or if it really isn’t a room temp superconductor, will at least lead to a proper room temp superconductor in the near future
Mind you, the DFT calculation from the Griffin paper is not a proof of LK 99 being a superconductor in any way. What it showed is the (potential) formation of flat bands near the Fermi surface. Band dispersion is associated with the kinetic energy of the electrons, so materials with flat band (and therefore electrons with suppressed kinetic energy) at the Fermi surface are more susceptible to interaction effect (and strong interaction causes all sorts of nonintuitive quantum effects). I’m not a DFT expert in any sense, but from what I’ve heard, it is quite easy to “tune” your model to produce narrow (the limit of which being flat) bands from substitutions (e.g. the Cu substitution in this case) and such, which don’t necessarily lead to superconductivity.
So I’ll take the DFT papers (there are quite a few now) as saying, “hey you want some flat band? Here’s some. We’ve done our part. Now some other theorist, do your magic and conjure up some superconductivity”. It’s a cog in the full picture, if there is a full picture