Pinned
Now that I have a captive audience…(welcome new followers!) a monster thread on what my paper says, the approximations and the caveats… (1/aleph)
Sinéad Griffin
8,034 posts
Sinéad Griffin
@sineatrix
@[email protected] 100% scientist @BerkeleyLab, 50% artist and 0% arithmetician, asesma.org, 🇮🇪 (she/her)
Berkeley, CA
Joined March 2009
- Replying to @sineatrixTLDR: My paper did *not* prove nor give evidence of superconductivity in Cu-apatite. It showed interesting structural and electronic properties that have features common with high-Tc superconductors provided Cu is in the right place. Otherwise we get a ‘boring’ semiconductor.
- What a time to be alive. ‘Graph networks trained at scale…discover 2.2 million structures… many of which escaped previous human chemical intuition…Of these, 381,000 entries live on the updated convex hull as newly discovered materials.’ LFG nature.com/articles/s4158…
- Replying to @sineatrixFirstly, it’s so exciting to see the interest in solid-state physics! Welcome to the most exciting subfield of physics ;) And thank you all for the interest!
- Replying to @sineatrixThe structural distortion and my magnetic calculations of Cu on the Pb(1) also suggest that there might be strong electron-phonon coupling or spin fluctuations in this system (important for the superconducting mechanism) END OF MEGATHREAD 1
- Gave my promotion talk yesterday. Here’s a very tired me enjoying the moment after sharing what we have done in the group since it all began in Jan 2019. 😴
- Promoted. 🍸Gave my promotion talk yesterday. Here’s a very tired me enjoying the moment after sharing what we have done in the group since it all began in Jan 2019. 😴
- Replying to @sineatrixFlat bands can mean superconductivity, but can also mean a wealth of other phenomena like metal-insulator transitions, charge density waves, magnetism (all interesting!)
- Replying to @sineatrixAwesome to see the discussions and explanations of the work, especially those aimed at non-experts. I wish I could keep up and spend more time in these discussions but y’all broke my twitter. My personal fav is that I managed to see is from @MarjBaldwin
- Replying to @sineatrixResult 2: The electronic structure of Cu on Pb(1) has isolated flat bands at the Fermi level. These are a direct result of the structural distortion! When I calculate the bands without the distortion, they are not isolated. When I include the distortion, they are!
- Replying to @sineatrixSimulation of #LK99 by Sinéad! Translation for children of the conclusions: if you put the copper impurity in the right place, you may see promising and spooky effects. However in practice it's easy to miss the spot and the impurity ends up elsewhere, where there's no magic.
- Since Cu on Pb(2) is more energetically favorable than Cu on Pb(1) we would expect conventional synthesis methods to favor Cu on Pb(2) over Pb(1). This might make obtaining Cu on Pb(1) more challenging.Replying to @sineatrixThe structural distortion and my magnetic calculations of Cu on the Pb(1) also suggest that there might be strong electron-phonon coupling or spin fluctuations in this system (important for the superconducting mechanism) END OF MEGATHREAD 1
- Replying to @sineatrixLooking at the structure, it didn’t look like something that would be high-Tc… why? A lot of the known high-TC materials are layered, and have substantial amounts of transition metals (e.g. Fe, Cu). This did not. Similar discussions on here including from @sentefmi
