作者leptoneta (台湾高山族自治区书记)
看板Physics
標題Re: [新聞] 韓國發現常溫常壓超導體
時間Tue Aug 1 12:09:27 2023
※ 引述《caseypie (吟遊詩人)》之銘言:
: https://arxiv.org/abs/2307.12037
: 材料是Pb_{10-x}Cu_x(PO_4)_6O
: 在室溫一大氣壓下測得零電阻和反磁性
: 麥斯納效應影片:https://sciencecast.org/casts/suc384jly50n
: 文章內詳細解釋了合成方法
: 作者只用了修正的BCS來解釋機制
: ----
: 要是真的,那韓國人真的要發明全宇宙了
就機制來說 National Lab是支持這個結果
https://twitter.com/Andercot/status/1686215574177841152
National Lab (LBNL) results support LK-99 as a room-temperature
ambient-pressure superconductor.
Simulations published 1 hour ago on arxiv support LK-99 as the holy grail of
modern material science and applied physics.
(
https://arxiv.org/abs/2307.16892)
以下為推特內文
Here's the plain-english explanation:
- The simulations modeled what the original Korean authors proposed was
happening to their material - where copper atoms were percolating into a
crystal structure and replacing lead atoms, causing the crystal to strain
slightly and contract by 0.5%. This unique structure was proposed to allow
this amazing property.
-
@sineatrix
from Lawrence Berkeley National Lab simulated this using heavy-duty compute
power from the Department of Energy, and looked to see what would happen to
the 'electronic structure' of this material, meaning, what are the available
conduction pathways in the material.
- It turns out that there are conduction pathways for electrons that are in
just the right conditions and places that would enable them to
'superconduct'. More specifically, they were close to the 'Fermi Surface'
which is like the sea-level of electrical energy, as in '0 ft above
sea-level.' It's believed currently that the more conduction pathways close
to the Fermi surface, the higher the temperature you can superconduct at (An
analogy might be how its easier for planes to fly close to the surface of the
ocean due to the 'ground effect' that gives them more lift.)
This plot in particular shows the 'bands', or electron pathways, crossing
above and below the Fermi surface.
- Lastly, these interesting conduction pathways only form when the copper
atom percolates into the less likely location in the crystal lattice, or the
'higher energy' binding site. This means the material would be difficult to
synthesize since only a small fraction of crystal gets its copper in just the
right location.
This is insanely bullish for humanity.
--
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※ 文章網址: https://webptt.com/m.aspx?n=bbs/Physics/M.1690862970.A.501.html
1F:推 peter308: 預定諾獎了? 08/01 12:44
2F:推 linbryan: 裏面提到這材料難做.因Cu難放在對位置.可預期雜質很多. 08/01 12:44
3F:→ linbryan: 我猜他只是測量bulk sample.如測量很小sample(lithograp 08/01 12:44
4F:→ linbryan: hy).有沒幫助?還有單high Tc並沒解決應用問題.重要在hig 08/01 12:44
5F:→ linbryan: h Ic, Hc. 08/01 12:44
6F:推 peter308: 似乎是用VASP 模擬的? 問題是第一原理模擬參雜系統 08/01 12:48
7F:→ peter308: 要建構的超晶包要很大 才能接近參雜的比率 08/01 12:49
8F:→ peter308: 有時候超晶包要到500-1000個原子 08/01 12:49
9F:→ peter308: 一般來說 就是看能待在費米能級附近有無平帶 08/01 12:50
10F:→ peter308: 但更嚴謹的作法要用EPW(electron-phonon wannier) 套件 08/01 12:51
11F:→ peter308: 去做更進一步的驗證 08/01 12:51
12F:→ meblessme: 如果好複現也不會丟出來了 08/01 12:52
13F:→ Bugquan: 問題是其它復現都沒做出來,不過目前聽說阿貢國家實驗室 08/01 12:53
14F:→ Bugquan: ,有跟他們接洽,要直接分析他們手上的成品 08/01 12:53
15F:→ meblessme: 不過這不是ai最擅長的嗎, 08/01 12:53
16F:→ meblessme: 接下來就看是人先找到還是ai先找到提高良率的辦法了 08/01 12:53
17F:推 peter308: 有人手上有XRD數據嗎? 我需要XRD的cif檔就夠 08/01 12:54
18F:→ peter308: 剩下的VASP我就能自己算 08/01 12:54
19F:→ Bugquan: 不過真的要是室溫超導,其它組沒復現,或是理論跟不上也 08/01 12:54
20F:→ Bugquan: 沒差,起碼東西拿出來讓大家有個方向,也確定真有室溫超 08/01 12:54
21F:→ Bugquan: 導 08/01 12:54
22F:推 KotoriCute: 沒人能復現那就就跟金屬氫差不多了 08/01 13:33
23F:推 Bugquan: 金屬氫那位大哥Ranga Dias,今年"也"搞出室溫超導 08/01 13:35
24F:→ yoyun10121: 這是模擬吧, 和復現是兩回事 08/01 15:16
25F:→ hank780420: 真的要cif檔直接連絡原團隊吧 他們連比對都用VESTA.. 08/01 15:44
26F:→ peter308: 下面那篇文章附錄已經有結構檔 08/01 15:51
27F:→ wohtp: 先不要說室溫啦,這鬼東西在10K是不是超導? 08/01 17:27
28F:→ wohtp: 我好像都沒看到有誰量這個。 08/01 17:27
29F:→ Eriri: 除去原作者 目前為止公開量過電阻的只有一組 沒有觀測到超 08/02 00:25
30F:→ Eriri: 導 08/02 00:25
31F:→ Eriri: 那篇文章量了150-300K的區間 08/02 00:27
32F:→ Eriri: 然後 DFT的那幾篇文章 都沒有證明有沒有超導 其實根本沒有 08/02 00:28
33F:→ Eriri: 處理超導 08/02 00:28
34F:→ Eriri: (事實上 哪怕宣稱證明了…DFT的結果都不一定可信…) 08/02 00:29
35F:→ Eriri: 磁浮效應則可能真的存在 看起來不同的影片都觀察到了 08/02 00:30
36F:推 shybaman: 以全世界沒人鳥,韓國教授崔東植發明的ISB超導模型為基 08/02 01:02
37F:→ shybaman: 礎,弄出來的室溫超導體 08/02 01:02
38F:推 linbryan: 一般磁浮只要夠輕dimagnetic +夠大磁場就可做到.YBCO磁 08/02 01:33
39F:→ linbryan: 浮實驗是強力小磁鐵磁浮在YBCO上.但這個像是磁浮在大磁 08/02 01:33
40F:→ linbryan: 鐵上 08/02 01:33
41F:→ Eriri: 今天又多了兩篇類似的DFT文章… 08/02 12:06
42F:推 peter308: DFT很簡單啊 難的是EPW的計算 08/02 12:45
43F:→ hank780420: 我也跟w大一樣覺得很奇怪 量測都要放到PPMS了 08/02 13:50
44F:→ hank780420: 4k-400k的R-T跟M-T都量出來基本的吧..... 08/02 13:51