tag:blogger.com,1999:blog-6911752388384243976.post7448762971794877060..comments2023-04-05T13:37:33.168+01:00Comments on IEC Fusion Technology: Room Temperature Superconductors One Step CloserM. Simonhttp://www.blogger.com/profile/09508934110558197375noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-6911752388384243976.post-42558330213674703332009-10-16T10:01:22.581+01:002009-10-16T10:01:22.581+01:00The information about topological insulators and s...The information about topological insulators and superconductors was interesting. Developing a room temperature superconductor would be useful since it could have a lot of applications.Unknownhttps://www.blogger.com/profile/17859355413834531138noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-22811362025485391302009-07-10T22:48:11.383+01:002009-07-10T22:48:11.383+01:00Amazing how far we've come in such a short tim...Amazing how far we've come in such a short time!! Keep doing what you're doing.. you guys.. ARE the REAL heroes of our world! Don't forget that fact!!Momma Bearhttps://www.blogger.com/profile/13433521041610590645noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-58254084643328323122009-06-23T20:52:28.223+01:002009-06-23T20:52:28.223+01:00Doug,
Thanks for that. If the guys writing the ar...Doug,<br /><br />Thanks for that. If the guys writing the article had just emphasized that spin was conserved it would have been a lot clearer.M. Simonhttps://www.blogger.com/profile/09508934110558197375noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-20264240109161461582009-06-23T15:57:30.406+01:002009-06-23T15:57:30.406+01:00Trust me - I'm a condensed matter physicist, a...Trust me - I'm a condensed matter physicist, and dissipationless spin currents in topological insulators have nothing to do with superconductivity, except in one very formal mathematical sense. <br /><br />Loosely speaking, in a superconductor, electrons pair up and those pairs "condense" into a particular kind of "fluid". That fluid can carry charge and flow without dissipation. That's because it costs a finite amount of energy to break up a pair. (In an ordinary metal one can dump an arbitrarily small amount of energy into the electrons. In a superconductor, if a process doesn't have enough energy to break a pair, it can't dump energy into the electrons.)<br /><br />In these topological insulators (note that they're bulk <i>insulators</i>), one can have spin currents, where more spin-up electrons flow one direction and spin-down electrons flow the opposite way. This kind of current transports <i>spin</i> (the magnetic moment of electrons) without dissipation, but it does not transport <i>charge</i>. Because they don't transport charge, you cannot use spin currents to, for example, run an electric motor. Now, you may be able to use spin currents in computing, since there are clever ideas about how to store information using spin. However, this has no application for power transmission or distribution. There are some other neat features of topological insulators, but these have nothing to do with superconductivity.<br /><br />The formal similarity between topological insulators and superconductors is that they both have an energy gap - it costs a certain minimum amount of energy to make a low energy excitation of the system. However, those excitations are very different things.<br /><br />You're right, of course, that a room temperature superconductor would be great, even if Jc and Bc are low. People are looking for such materials, but not these folks.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-37149347760627389502009-06-23T05:28:15.251+01:002009-06-23T05:28:15.251+01:00No loss of energy sounds like a superconductor to ...No loss of energy sounds like a superconductor to me. Jc may be severely limited but there are still a lot of uses in electronics for a low Jc room temperature superconductor.M. Simonhttps://www.blogger.com/profile/09508934110558197375noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-61622906237218912312009-06-23T04:40:57.695+01:002009-06-23T04:40:57.695+01:00I hate to break it to you, but this material has n...I hate to break it to you, but this material has nothing whatsoever to do with superconductivity.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.com