Talk:Topological insulator

Rewrite

I have rewritten this page to try to make it better organized and more accessible to non condensed matter physicists. I tried to include as much of the original material as possible, but if there is anything that was left out please add it back in. Cheers A13ean (talk) 01:31, 6 August 2010 (UTC)

Thanks for all the help clarifying, expanding and fixing errors! A13ean (talk) 21:35, 9 August 2010 (UTC)

I'm not criticizing the article, and I didn't look at the other references. But I'd never heard of this before, and I found a blog with an explanation which was a lot more clear to me, so I added it.

It's mentioned at the beginning of the Big Bang Theory episode "The Thespian Catalyst" when Sheldon is giving a lecture and nobody likes the way he lectures. But I wasn't sure about adding a "Popular Culture" section to the article.

99.9.112.31 (talk) 15:35, 4 November 2011 (UTC)NotWillDecker

Band inversion

There is a reference to 'band inversion' but we don't have an article on it under that name. Is there a different name we should link to? RJFJR (talk) 01:58, 8 November 2011 (UTC)

As far as I know this is not discussed anywhere, I will try to add an explanation into the text later. A13ean (talk) 15:57, 8 November 2011 (UTC)

Joel E Moore article in IEEE Spectrum

In addition to Feb 2011 article already referenced by article, there's another article by same author in IEEE Spectrum here: http://spectrum.ieee.org/semiconductors/materials/topological-insulators/0. Cheers, Rayshade (talk) 23:49, 6 April 2012 (UTC)

Section: A comparison between topological insulator, trivial band insulator, and intrinsic topological order

This section is currently not very readable, and not entirely encyclopedic in tone. Anyone want to take a stab at cleaning it up? a13ean (talk) 03:55, 17 November 2012 (UTC)

@a13ean I am not sure whether this section is necessary at all. Perhaps a sentence that these shouldn't be confused and a reference to topological order? Anton.akhmerov (talk) 03:21, 21 November 2012 (UTC)--

Yeah, the more I try to make sense of it the more my brain hurts and I think you're right. a13ean (talk) 03:43, 21 November 2012 (UTC)

Samarium Hexaboride in Nature

Nature has an article[1] about samarium hexaboride possibly being a topological insulator. There are a few papers on arXiv regarding this. Would this information be appropriate to add to the article, or does it need to be published in a peer reviewed journal first? -W0lfie (talk) 18:40, 12 December 2012 (UTC)

Using the very second sentence of the article to say that samarium hexaboride might be a TI seems excessive. This should be removed or moved to somewhere down in the article. The article doesn't even mention the more "popular" TIs like Bi_2Se_3. --128.101.214.142 (talk) 18:42, 13 December 2012 (UTC)

I agree with 128.101.214.142. Bismuth compounds should be given more attention in the paper. Samarium hexaboride on the other hand is in a very early stage of its development. Anton.akhmerov (talk) 18:47, 13 December 2012 (UTC)

It would be great if someone explained what those things are in the lead, so that people without a doctorate in chemistry can understand them. Diego (talk) 21:34, 13 December 2012 (UTC)

Lots of materials have been predicted to be TIs in published papers, but it's probably not worth mentioning them explicitly unless there's been an experimental study. a13ean (talk) 17:16, 20 December 2012 (UTC)

Relevance of the reference to graphene ?

I'm not a condensed-matter physicist, so the reason for the sudden mention of graphene in (what is currently) the third section ... seems meaningless. I understand that graphene is a "hot" subject ; that it has many intrinsically 2-dimensional properties (like "surfaces" in general), but the specific relevance of "topological insulators" to graphene ... I don't see what the significance is. So ... C-M physicists, to whom the relevance is blindingly obvious, please expand this a bit. Aidan Karley (talk) 13:33, 20 December 2012 (UTC)

I think someone was trying to distinguish topological insulators from other edge state physics, but the graphene bit was rather misleading since it sounded like it was referring to its normal properties rather than the quantum hall effect. It would be nice if someone could make a free version of the first image in K&M's overview here at some point. a13ean (talk) 17:14, 20 December 2012 (UTC)

That reference is very likely regarding the nature of the surface state. In the band diagram, note how the surface state has linear dispersion, just like the Dirac cone in graphene. --128.189.122.39 (talk) 03:20, 21 March 2013 (UTC)

This article is too technical

— 69.165.160.86 (talk) 01:25, 13 July 2013 (UTC)

Thanks for your concern… could you please be more specific? — |J~Pæst|  04:01, 13 July 2013 (UTC)

I agree that it is too technical. It is almost meaningless to me. My particular complaint is that the "Properties and applications" section does not seem to list any applications. An application I am interested in is third rail electric railways. I'm looking for a material which would conduct while a train was drawing current from it and become an insulator after the train had passed. Would Topological insulators be relevant to this? Biscuittin (talk) 22:48, 8 March 2014 (UTC)

Hmm. dont worry about it, I have a PHD in physics, albeit from the 1990s, but in lasers and fibre optics, and I dont understand it either, you are certainly not alone - though I would not say its too technical, it's just not made clear !! Having looked up the explanatioin of T-symetry to see if I could crack what the first scentance was actually on about, I've given up, it needs a modern solid state physics person who speaks english to look at both those articles and add some introductory words , regards,

Mike Page-Jones. .  — Preceding unsigned comment added by 78.147.186.152 (talk) 17:25, 29 March 2014 (UTC) 

Ok, this is in the news now. I really hope some editor can whip this into shape for a layperson. if a physics phd cant comprehend it, no one can. I have absolutely no idea what it is from this article. I wish i hadnt read it, now i feel like an idiot. can someone channel feynman and fix this?(mercurywoodrose)76.254.32.94 (talk) 04:42, 24 September 2014 (UTC)

agree, way way to technical in intro, remmber, rule of thumb for wiki, your mom or dad should be able to understadn the intro — Preceding unsigned comment added by 2601:6:3880:CC8:600C:D92F:81A3:A4ED (talk) 03:50, 8 December 2014 (UTC)

This problem persists ... :(. Accordingly, I've flagged the page with the {{technical}} template. My physics studies at university finished almost 50 years ago, and despite my abiding interest (and voracious reading) in all things to do with physical science, particularly particle physics and materials science, I couldn't make enough sense of most of the statements here to be able to bluff a TV show host ...! Please, if you have any idea:

a) what topological insulators look like,
b) where they may be found, or
c) why they matter ...

do enlighten us all! yoyo (talk) 14:54, 16 August 2016 (UTC)

There's some good news! The reference by Marcel Franz cited in the linked Axion article explains the reference by Qi et al ("the Stanford group"), also in the Axion article, in broad terms. It provides a much clearer idea of what and why; there's even a picture! - a colour illustration of the quantum Hall effect, and of quantum electron induction by an applied magnetic field. Franz actually explains what θ (theta) is: "θ describes the strength of the axion field" and then describes the difference between ordinary and topological insulators in terms of allowable quantum values of θ.  :). Wish he wrote for Wikipedia! yoyo (talk) 15:45, 16 August 2016 (UTC)

Topological insulator growth

A new article Topological insulator growth has appeared. However it covers quite a bit of the same content as this article. But a couple of sections could be moved into here. Graeme Bartlett (talk) 23:49, 30 July 2018 (UTC)

Agree, and went one step further be merging it all; there is a coninuum between experimental verification and growth best discussed in one place, and the significant overlap in the existing content elsewhere in the articles was certainly worth consolidating. Klbrain (talk) 09:46, 24 August 2019 (UTC)

  Y Merger complete.

What units used to measure surface conductivity

What units are used to measure surface conductivity - Is it Siemens per square (independent of dimension) as for sheet resistance ? Have any TI been measured ? - Rod57 (talk) 14:02, 16 September 2018 (UTC)

Is Z-2 the same as $\mathbb {Z} _{2}$?

The second paragraph talks of Z-2 topolical invariants, in the reference typseset at $Z_{2}$. Should this be $\mathbb {Z} _{2}$ like the symmetry group, also used later in the introduction? CyreJ (talk) 10:41, 19 May 2022 (UTC)

Yes, it should be the same. Go ahead and edit. 163.1.18.5 (talk) 13:07, 12 July 2022 (UTC)

good to note that very many materials are topological in some conditions

c.f. VERGNIORY, WIEDER, ELCOROSTUARTet. al https://doi.org/10.1126/science.abg9094 — Preceding unsigned comment added by 68.123.8.175 (talk) 02:16, 20 May 2022 (UTC)

Wiki Education assignment: Public Writing Fall 2022 F1

This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 September 2022 and 12 December 2022. Further details are available on the course page. Student editor(s): ProbablyOrthogonal (article contribs). Peer reviewers: Dontbotherme123, Sobervicodin, Thelegolady, Toggle78.

— Assignment last updated by Sobervicodin (talk) 18:06, 5 October 2022 (UTC)