tag:blogger.com,1999:blog-13869903.post3333577642065701487..comments2024-03-28T04:15:44.459-05:00Comments on nanoscale views: What are universal conductance fluctuations?Douglas Natelsonhttp://www.blogger.com/profile/13340091255404229559noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-13869903.post-48213834182411182072018-09-21T12:09:59.683-05:002018-09-21T12:09:59.683-05:00Nice explanations. However, I would still like to ...Nice explanations. However, I would still like to point out a key point, that UCF are not at all necessarily universal, not on the order of e2/he2/h.<br /><br />We have some numerical and analytical generalizations of UCF to anisotropic systems, where the UCF amplitude really depends on the detail of the material(Ref:https://journals.aps.org/prb/abstract/10.1103/PhysRevB.96.134201).<br /><br />I would say, UCF is universal in that it exists and have predictable values. But 'universal' does not mean 'same' or even 'similar'.Anonymoushttps://www.blogger.com/profile/07385101530002024780noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-8533745261865739442015-09-12T22:36:29.917-05:002015-09-12T22:36:29.917-05:00Very nice explanation, maybe next you can post on ...Very nice explanation, maybe next you can post on 1/f noise...Ali Alsaqqahttps://www.blogger.com/profile/05692878049210236604noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-44609473823148077202014-07-25T05:05:50.629-05:002014-07-25T05:05:50.629-05:00Thanks for this post. Seems like there’s always so...Thanks for this post. Seems like there’s always something new I learn even after being in the field for 25 years…e.l.http://www.cocoon-bobbin-oil.comnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-58476772316139256422014-07-10T22:12:28.664-05:002014-07-10T22:12:28.664-05:00Igor, (at least) CDWs located (purely) at surfaces...Igor, (at least) CDWs located (purely) at surfaces is reasonably active, though in a small community. Examples are 2D 1/3 ML of Sn on Ge, and lately quasi 1D Au "wires" on vicinal Si and on Ge surfaces.<br />Finding ("seeing") SDWs in these systems, or doing transport (entering the mesoscopic regime) is hard though.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-67773432869815644242014-07-10T10:52:35.114-05:002014-07-10T10:52:35.114-05:00Great post. You should discuss CDW/SDW next -- th...Great post. You should discuss CDW/SDW next -- the "old" book by Grunner is the bible of it. This field seems (almost) entirely overlooked now, I suppose because CDW research peaked just before the discovery of High-Tc cupratesIgor Fridmanhttp://www.physics.utoronto.ca/~ifridmannoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-53536165006405972962014-07-07T23:04:34.916-05:002014-07-07T23:04:34.916-05:00The amusing turn is that a key idea in many-body l...The amusing turn is that a key idea in many-body localization is in some sense the opposite of those controversial (and erroneous) 90s claims of zero-temperature dephasing. To get MBL you need the failure of dephasing at T = T_c > 0. It means your macroscopic sample becomes "mesoscopic" at finite temperature!Matthew Fosterhttps://www.blogger.com/profile/17461175352564741190noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-24847210295496084062014-07-03T08:48:42.095-05:002014-07-03T08:48:42.095-05:00Doug,
yes I am (surprised); in my view the mesosc...Doug, <br />yes I am (surprised); in my view the mesoscopic point of view should be studied especially when dealing with (mesoscopically!) phase separated bulk materials. <br /><br />And that includes high Tc, domains in multiferroics, density waves, CMR manganites etc.<br />Considering that electronic coherence lengths are generally short in strongly correlated systems, the mesoscopic toolbox can be applicable here at quite small lengthscales.<br /><br />Anyway, I appreciate the wide variety of subjects you present here.<br />Keep up the good work.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-61263616275317921802014-07-01T08:41:41.420-05:002014-07-01T08:41:41.420-05:00Anon, you'd be surprised. I think part of it ...Anon, you'd be surprised. I think part of it is that the strongly correlated electron community (e.g., high Tc, heavy fermions, multiferroics, CDW/SDW/orbital ordering/CMR, frustrated magnetism) has historically worked a lot with bulk materials. Additionally, that community has viewed transport as a tool to look at the Fermi surface (bulk resistivity, quantum oscillations) and spectral response (optical conductivity). They just have been asking different questions.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-41615996145137232512014-07-01T04:38:17.186-05:002014-07-01T04:38:17.186-05:00Good work as a young person.Good work as a young person.Anonymoushttps://www.blogger.com/profile/11862142727587164193noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-34746467199616862222014-07-01T04:36:36.448-05:002014-07-01T04:36:36.448-05:00nice work procedure.so it can be help for next gen...nice work procedure.so it can be help for next generation.Anonymoushttps://www.blogger.com/profile/11862142727587164193noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-49434671474806699662014-06-30T22:23:18.790-05:002014-06-30T22:23:18.790-05:00From a young person (PhD '06) I am a bit surpr...From a young person (PhD '06) I am a bit surprised: doesn't everybody that at least looks at transport experiments in either complex materials or lithographically defined materials (i.e. not in the bulk of "boring" materials) study Datta's Electronic transport in Mesoscopic systems?<br /><br />To me that is the bible of mesoscopic physics of electron transport, just like Sze is the bible of semiconductor devices.<br /><br />It's good to just get a 20 yr old book and study instead of read all the new fancy papers in PRL...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-44966533106807825532014-06-30T13:40:46.924-05:002014-06-30T13:40:46.924-05:00As a younger person in condensed matter physics wh...As a younger person in condensed matter physics who has heard of but never studied conductance fluctuations, thanks for the post! The analogy with a laser speckle pattern was quite enlightening.Ted Sandershttps://www.blogger.com/profile/15001183656827732917noreply@blogger.com