Talk:Spin ice

Magnetricity

http://news.bbc.co.uk/2/hi/technology/8307804.stm

I think this is relevant. —Preceding unsigned comment added by 71.122.71.250 (talk) 00:17, 15 October 2009 (UTC)

Proposed reorganisation

Please see here for what I propose! Chris 21:48, 29 June 2007 (UTC)

Difficulty of making ice crystals

The article twice mentions the difficulty of making single pure ice crystals, but fails to explain the reasons. Could someone amplify a little? Kay Dekker (talk) 20:18, 14 October 2009 (UTC)

Edit 2010MAR26

I have completely rewritten the opening paragraph, which I think was previously rather misleading. 'Spin ice' certainly doesn't refer to a property of water ice: it refers to a set of compounds containing spins with closely related properties to water ice (hence the name). I also think describing emergent magnetic monopoles as "not technically magnetic monopoles" is not sufficiently objective for Wikipedia. They aren't 'fundamental' magnetic monopoles, but they are certainly monopoles in the magnetic field. I have also eliminated the reference to tetrahedra in this paragraph; the most important compounds have pyrochlore structures, but this isn't a defining characteristic. Stevvers (talk) 13:47, 26 March 2010 (UTC)

I'm sorry, but after reading the intro paragraph I still have no idea what spin ice is. Some things that need to be defined inline are:

• frustrated magnetic compounds: The wiki link to geometrical frustration does not help at all.
• large residual entropy: What does this imply in layman's terms? What observable property does this impart to the example (water ice) and to spin ice?
• deconfined magnetic monopoles (with analogous properties to the hypothetical magnetic monopoles postulated to exist in the vacuum): What properties? I might have an inkling of what a magnetic monopole is, but what is a deconfined magnetic monopole? Is it an important distinction to someone who just wants to know what spin ice is?

In short, the introduction paragraph MUST be intelligible to someone with a basic (high school) physics background. If you can't explain geometrical frustration in English in the intro paragraph, it will lead to human frustration when the rest of us non-physicists try to read it. Move jargon into the body. --RabidDeity (talk) 18:53, 3 May 2010 (UTC)

It's going to be tricky to write an opening paragraph that isn't either difficult for the layman, hopelessly vague, or extremely long, but we can try. To start with, when you say the link to geometrical frustration doesn't help, do you mean that we shouldn't rely on a link to define this, or that (the opening paragraph of) that article isn't clear enough? Stevvers (talk) 18:40, 4 May 2010 (UTC)

Including the link to satisfy a reader's desire to learn more is certainly important, but I would agree that relying on that link to define geometrical frustration maybe isn't the best idea. Partially it's because the intro paragraph to that article is poorly written, and partially because our attempted definition is worse than the link- we try to define it using other terms a reader outside the field of quantum physics won't understand ("spin degrees of freedom").

An aside: contrast with Condensed matter physics, which provides multiple "anchors" to concepts the reader is familiar with. "The most familiar examples of condensed phases are solids and liquids, which arise from the electromagnetic forces between atoms." That third sentence ties the entire first paragraph together using a great example. (Note: the example doesn't even have to be technically perfect!) The second paragraph explains how the concept relates to other fields without using a lot of jargon. "Chemistry? Materials science? Nanotechnology? Okay, I kinda see where this is going. Ah, so this is why all those particle physicists want to figure this stuff out!" The third refers to where the field came from, which might also give clues about related fields I may have read about. Even though I might not be able to understand the body of the article, the intro provides enough information to both define the term and to determine what fields I might need to read up on, and where to start-- it's a sort of signpost that says, "Here are the basics, and to really grasp this you need to understand X and Y first." Does that help clear things up? RabidDeity (talk) 04:20, 6 May 2010 (UTC)

I can "confirm" (as a college-educated, technical-minded person with little specific knowledge of particle physics) that part of the problem with the geometrical frustration link is that its own intro is too technical. As it currently stands, here's how the opening paragraph parses when I read it...

Geometrical frustration is a phenomenon in condensed matter physics in which the geometrical properties of the crystal lattice or the presence of conflicting atomic forces forbid simultaneous minimization of the interaction energies acting at a given site. This may lead to highly degenerate ground states with a nonzero entropy at zero temperature.

Honestly, as soon as my eyes hit "forbid simultaneous minimization", they glaze over and I'm done for. FeRD_NYC (talk) 12:27, 22 March 2011 (UTC)

It sounds like the problem is then with that article, rather than with the link in this one. Stevvers (talk) 13:43, 3 May 2011 (UTC)

I added a first sentence without jargon Bhny (talk) 15:37, 2 May 2011 (UTC)

Thanks for the modifications to the opening; something like this was clearly necessary. But I'm not very happy with the phrasing: "A spin ice is a substance that is similar to water ice in that it can never be completely frozen. This is because it does not have a single minimal-energy state." While these statements are true (given an appropriate definition of 'frozen'), they sound like a definition, but they are too general. "Spin ice" refers a very specific class of frustrated materials, whereas these descriptions could apply to any frustrated materials. Stevvers (talk) 13:43, 3 May 2011 (UTC)

thanks for the comment. I see your point. how about- "A spin ice is a class of substances that has similar magnetic properties to water ice. A spin ice cannot be frozen because it does not have a single minimal-energy state." Bhny (talk) 15:05, 3 May 2011 (UTC)

"similar magnetic properties to water ice". Like, being diamagnetic? Needs more work, I'm afraid... Chris (talk) 15:40, 3 May 2011 (UTC)