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LK-99 in retrospect — LessWrong

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About a year ago, there was a lot of public interest in a supposed room-temperature superconductor called LK-99. What I publicly said at the time was, basically: We should remember the possibility that apparent levitation is from ferromagnetism or paramagnetism. Iron filings can stand up on a magnet, and pyrolytic graphite can float over a strong magnet. If we consider some known high-temperature superconductors: YBCO has flat sheets of copper oxide, and superconductivity happens along those planes. The copper in that has high positive charge density, comparable to aluminum atoms in alumina, which gives strong bonding to the oxygen. H3S (paper) has unusually strong bonds between the sulfur and hydrogen, which only form because the atoms are pressed into each other with enough pressure to substantially compress liquid water. Superconductivity comes from flow of Cooper pairs, and the electron-phonon interaction must be stronger than random thermal movement. LK-99 doesn't seem to have any

x LK-99 in retrospect — LessWrong Physics Postmortems & Retrospectives Social & Cultural Dynamics Frontpage 74 LK-99 in retrospect by [anonymous] 7th Jul 2024 Linkpost for www.bhauth.com 4 min read 21 74 About a year ago, there was a lot of public interest in a supposed room-temperature superconductor called LK-99 . What I publicly said at the time was, basically: We should remember the possibility that apparent levitation is from ferromagnetism or paramagnetism. Iron filings can stand up on a magnet, and pyrolytic graphite can float over a strong magnet. If we consider some known high-tempera

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