tag:blogger.com,1999:blog-13869903.post3479528514996832273..comments2024-03-29T02:45:10.096-05:00Comments on nanoscale views: Phil Anderson and the end of an eraDouglas Natelsonhttp://www.blogger.com/profile/13340091255404229559noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-13869903.post-46479139147352815222020-04-16T00:00:41.153-05:002020-04-16T00:00:41.153-05:00Thank you for the nice post. I should add two othe...Thank you for the nice post. I should add two other seminal contributions from PWA:<br /><br />* The very early work at Bell on the microscopic origin of the ferroelectric transition in perovskites done under Shockley <br /> (the papers have been reprinted in "A career in theoretical physics"). <br /><br />* The work with E. I. Blount (Phys. Rev. Lett. 14, 217 (1965)) where they predicted that ferroelectric-like transitions can in principle occur in metals. This was observed in LiOsO3 a few years ago and has given rise to the very active field of a polar-metals. Gian G. Guzmán-Verrinoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-10481280177978259072020-04-01T08:28:28.287-05:002020-04-01T08:28:28.287-05:00Phil would be proud...maybePhil would be proud...maybeAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-2825883058662036082020-04-01T03:26:23.417-05:002020-04-01T03:26:23.417-05:00Speaking of high-temperature superconductivity, th...Speaking of high-temperature superconductivity, this new approach made possible by COVID-19 seems promising: https://arxiv.org/abs/2003.14321 Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-59141096008875464702020-03-31T09:12:08.679-05:002020-03-31T09:12:08.679-05:00One last thing-about the TLS picture. After 5 deca...One last thing-about the TLS picture. After 5 decades finally computer simulation is up to the task of testing the picture-see: https://arxiv.org/abs/1910.11168 ...also discussed (a little bit) here:<br /><br />https://www.quantamagazine.org/ideal-glass-would-explain-why-glass-exists-at-all-20200311/David Reichmannoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-78975408973591955752020-03-31T08:26:56.774-05:002020-03-31T08:26:56.774-05:00Hi Doug-absolutely. Actually your point (7) is wh...Hi Doug-absolutely. Actually your point (7) is what I meant by my (2).David Reichmannoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-37346935898695102472020-03-31T08:19:59.254-05:002020-03-31T08:19:59.254-05:00And my link broke. I meant http://nanoscale.blogs... And my link broke. I meant <a href="http://nanoscale.blogspot.com/2009/10/unreasonable-effectiveness-of-toy-model.html" rel="nofollow">http://nanoscale.blogspot.com/2009/10/unreasonable-effectiveness-of-toy-model.html</a>.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-65363534889391107932020-03-31T08:09:05.002-05:002020-03-31T08:09:05.002-05:00David, yes, and there are more. As I have been rem...David, yes, and there are more. As I have been reminded via email by others:<br />6. The pseudogap (with relevance to spin and charge density waves, with Lee and Rice, Solid State Communications, 14(8), 703-709 (1974)).<br />7. Motional narrowing of spectral lines (Journal of the Physical Society of Japan, 9(3), 316-339 (1954)).<br />8. The original spin liquid/resonating valence bond paper (Materials Research Bulletin, 8(2), 153-160. (1973)).<br />9. Starquakes, glitches in neutron stars, and superfluidity of degenerate neutron matter (Nature, 256(5512), 25-27 (1975)).<br /><br />The Anderson/Halperin/Varma model of two-level systems in glasses was the major basis for my doctoral thesis, and I should have linked to this post about it.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-85575016847274158912020-03-30T16:34:41.020-05:002020-03-30T16:34:41.020-05:00There are a bunch of other seminal Anderson contri...There are a bunch of other seminal Anderson contributions:<br />1.Anderson-Halperin-Varma TLS model of low temperature glasses.<br />2."Kubo" theory of stochastic line shapes prior to Kubo (Anderson's PhD thesis).<br />3.Theory of double exchange and superexchange.<br />4.Seminal contributions to scaling and RG via "poor man's" scaling approach to Kondo model (Anderson-Yuval-Hamann).<br />5.Anderson's theorem describing protection of s-wave superconductivity against disorder.<br /><br />I'm sure there are others...David Reichmannoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-7077785825291193702020-03-30T13:44:15.737-05:002020-03-30T13:44:15.737-05:00Nice story, PPP. The other piece of physics I tho...Nice story, PPP. The other piece of physics I thought about including was what is now known as <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.18.1049" rel="nofollow">the Anderson orthogonality catastrophe</a>, which I'd mentioned <a href="http://nanoscale.blogspot.com/2013/11/the-orthogonality-catastrophe.html" rel="nofollow">here</a>.<br /><br />My other PWA anecdote: During "dead week" senior year of undergrad (between the end of classes and the start of finals), some of the graduating physics majors decided to have a cookout on the Jadwin loading dock, with beer, at the end of the day on (I believe) a Friday. PWA drives up and parks his car, some big old steel behemoth, behind the building and comes up via the loading dock to get inside. He looked at us curiously for a second, then realized what was going on, gave a little half-smile and kept walking. I offered him a beer, and he very politely said, "No, thank you" and went into the building. For someone who could be prickly, he seemed pretty amused.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-11288697177703989772020-03-30T12:47:02.508-05:002020-03-30T12:47:02.508-05:00Beautiful sentiments, Doug. There are countless co...Beautiful sentiments, Doug. There are countless contributions that Phil Anderson made to physics, of course. You did a great job highlighting most of them, but I'd like to add another (and other posters will certainly have more) that, arguably, was his most broad-ranging and influential work, perhaps even moreso than the Higgs. <br /><br />I am talking about his development with Sir Sam Edwards of the "replica" theory of spin glasses, as exemplified by the Edwards-Anderson Hamiltonian, and the corresponding application of the replica method and mean field theory to its analysis with Thouless and Palmer. This work laid the foundation for a more complete solution to the spin glass problem by Toulouse and Parisi, and the ideas and concepts from spin glasses that emerged have found application in areas as diverse as neural networks / deep learning, protein folding, evolution, and countless other disciplines well beyond the realm of 'traditional' physics.<br /><br />However, despite being such a great physicist, I think I will most remember Phil for his graciousness and generosity.<br /><br />I had the good fortune of meeting Phil once in my life. I was a second-year graduate student helping to organize a student-run conference for condensed matter physics, and we decided to invite Phil. I remember how nerve-wracking it was introducing P.W. Anderson to a room of condensed matter physicists - I felt like a college basketball player introducing Michael Jordan. In fact, I said exactly that in my introduction, and in response, Phil smiled, laughed and said "Nice introduction!" that made me feel more confident in myself.<br /><br />At dinner afterwards, I got the chance to talk to him personally some more. I was still very young, and in the early, difficult stages of graduate school, where I was coming to grips with just how little physics I really knew. I was still trying to figure out how to 'do' research. I told Phil about the confusion I was having in not knowing exactly how I should be approaching my problem, and asked him if it was normal to just feel like you were 'winging it' sometimes. He was so down-to-earth and easy going, and answered my questions in a casual, friendly tone, without being arrogant or condescending at all. <br /><br />Phil must have had tens of thousands of interactions with people from all walks of life, and I doubt he remembered me much, if at all. But to me, it was one of the biggest highlights of my career. Phil Anderson was my hero, and I had always been told 'never meet your heroes', since they would inevitably fall short of expectations. But I was lucky enough that my hero was one of the few that didn't.Pizza Perusing Physicisthttps://www.blogger.com/profile/02213655278674258393noreply@blogger.com