Talk:High-temperature superconductivity

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Contents 1 relation to room-temperature superconductivity? 2 Low temperature superconductors 3 Merge 4 Hydrogen 5 Naming 6 Proposed restructuring + expanding 7 Materials 8 Dummy sections 9 bbc article about htsc 10 possible copyright infringement 11 Pressure mounts for HTSC.

[edit] relation to room-temperature superconductivity?

Crowdyour, you changed the intro section to say:

A consistent theory of cuprate compounds does not currently exist; ... interest in this field is beyond the goal of achieving the room-temperature superconductivity.

This is almost the opposite of what I wrote before. But I must admit that the intro was very unclear before and I took a guess at what the original author was trying to say.

How does high-temp SC compare to room-temp SC? Is one seeing more research than the other? Is room-temp more or less likely to happen?

I assumed that room-temp SC was unlikely, and therefore more research is going into "high" temp SC. But obviously someone who knows needs to clarify.

Also, "the" should not appear before "room-temperature superconductivity". (English)

[edit] Low temperature superconductors

It is not true that "low temperature superconductors" always needs liquid helium temperatures. Generically, "low temperature superconductors" are defined by not being "high temperature superconductors". This just means that they are described by the conventional BCS theory. For instance, magnesium diboride (MgB2) is the most recently discovered conventional superconductor, and it has a Tc of 35K. The BCS theory describes "phonon mediated" electron pairing. Although it cannot predict Tc, there are general arguments that say that Tc can not get above 30-35K.

Some contemporary hi-Tc theories try to invoke phonons, but there is no consensus on their applicability. The largest peice of evidence against phonons is the lack of "isotope effect", where Tc is proportional to the square root of the mass of the isotopic substitution element. The extended BCS theory, which generalizes weak coupling phonons to stronger coupling, known as the Eliashberg theory, predicts that the exponent will not be exactly 1/2, but will be material dependent. —Preceding unsigned comment added by 24.86.198.146 (talk • contribs) 05:28, 26 November 2004

[edit] Merge

This page should be merged with High-temperature superconductors 220.244.224.10 00:36, 16 Mar 2005 (UTC)

[edit] Hydrogen

Why it seems like there's no study on this together with the first element? --Cacumer 18:33, 3 February 2006 (UTC)

[edit] Naming

I've been out of the field for too long to make good contributions to this article. But "back in the day" I actively avoided the term "high temperature" to describe these materials. Yes, it's high compared to the Tc of Nb3Sn, but 100 Kelvin is not "high" in any absolute sense. What will we call the 200 K superconductors of the future? "Collosal High Temperature"? I propose "perovskite superconductors" or "cuprate superconductors", unless those terms have died out. Spiel496 23:30, 7 April 2006 (UTC)

The term "high-temperature superconductor" is definitely well established and current in this context --spiralhighway 00:07, 14 June 2006 (UTC)

I agree, the term "high-temperature superconductor" is a widely used term. Besides, high and low temperature is not meant to be an absolute scale. When studying neutron start, 10^8 K is a low temperature. The Kondo effect is a low temperature effect, and can occur around 400 K. Similarly, 100 K is a high temperature for superconductivity to occur. Also, I feel high-temperature superconductor is a better term than "perovskite superconductors" or "cuprate superconductors", since not all high-tc superconductors are perovskite or cuprates, take the ruthenates for example. PhysicsBob 13:32, 6 November 2007 (UTC)

[edit] Proposed restructuring + expanding

Maybe we can improve this article by introducing some sections to it. Here's my first cut at a proposal, please feel free to edit / change / add mercilessly:

• Background - mostly stuff that's already there
• Theory - contending theories, description of Anderson RVB model
• HTSC research overview - including the main motivations for it, what's known, the big outstanding questions
• Maybe 2 sections about specific research questions in the field
• Applications - applications of current HTSC materials
• Research groups - maybe a list of major research groups around the world and their fields of specialization

--James Slezak 01:15, 21 June 2006 (UTC)

I agree with this structure in principle, but perhaps the section on Research Groups could be dropped, since it wouldn't tell us much about high-tc superconductors. Also, I think the theory could be a bad idea, since it is probably one of the most contentious points in physics at the moment, and nobody seems to know really what they're doing. Conversely, it is a good idea since it will give readers an idea about what people think about high-tc at present. PhysicsBob 13:36, 6 November 2007 (UTC)

[edit] Materials

It seems that many of the materials listed are very out of date. Also, no mention of nanotubule research Dtsvaro 08:47, 30 July 2006 (UTC)

As I understand it, carbon nanotubes reach superconductivity at about 20K, making them low-temperature superconductors. YBCO was still the leading class of high-temp ceramics when I was working in a lab 3 years ago... I can't comment on advances since then. Garrepi 07:51, 17 August 2006 (UTC)

It appears that high temperature superconductivity early reports of CNT = carbon nano tubes has not been confirmed. Other types of nano tubes, perhaps. Ccpoodle 17:53, 22 July 2007 (UTC)

[edit] Dummy sections

I'm commenting these out. I assume they're being used as guidelines for future development, but the article needn't look like a skeleton in the interim. Chris Cunningham 10:49, 22 February 2007 (UTC)

[edit] bbc article about htsc

http://news.bbc.co.uk/2/hi/technology/6412057.stm

i think that's interesting and a good source. —The preceding unsigned comment was added by 80.133.226.122 (talk) 09:57, 6 March 2007 (UTC).

[edit] possible copyright infringement

Chapter 'How High-Temperature Superconductors are Made' seems to be very similar to the last chapter 'How does STI make its thin-film microelectronics, or microchips?' on http://www.suptech.com/tech_faq.htm 84.231.69.60 19:01, 28 June 2007 (UTC)

True. However, given how short the section is, I think we can get away with using it as a reference. It's not a 1:1 copy, although that's clearly where it was taken from. Thanks. Chris Cunningham 19:10, 28 June 2007 (UTC)

[edit] Pressure mounts for HTSC.

http://www.eetimes.com/news/latest/showArticle.jhtml;jsessionid=HTTOTGYXPCPWSQSNDLSCKHA?articleID=206904213 —Preceding unsigned comment added by 82.131.210.162 (talk) 11:38, 20 March 2008 (UTC)