Physicists discover new quantum electronic material | Hacker News Reader

Physicists discover new quantum electronic material

news.mit.edu

83 pointsjonbaer13 comments

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Here's the original paper, for those interested:

https://arxiv.org/abs/1709.10007

Looks to be from September of 2017.

Unrelated but:

Surprise graphene discovery could unlock secrets of superconductivity https://news.ycombinator.com/item?id=16627914

The article seems to indicate that this is a high temperature (room temperature?) superconductor. That would be a massive discovery if true. Can someone more enlightened comment on this?

>When they flowed a current across the kagome layers within the crystal, the researchers observed that the triangular arrangement of atoms induced strange, quantum-like behaviors in the passing current. Instead of flowing straight through the lattice, electrons instead veered, or bent back within the lattice.

>This behavior is a three-dimensional cousin of the so-called Quantum Hall effect, in which electrons flowing through a two-dimensional material will exhibit a “chiral, topological state,” in which they bend into tight, circular paths and flow along edges without losing energy.

>“The charges in the crystal feel not only the magnetic fields from these atoms, but also a purely quantum-mechanical magnetic force from the lattice. This could lead to perfect conduction, akin to superconductivity, in future generations of materials.”

Room temperature exotic behaviour, but not specifically superconduction.

Towards the end of the article, it suggests dissipationless power lines as an application.

Whether "dissipationless" is equivalent to "superconducting" I'm not sure; but it sounds the same to me ;)

I presume another application could be higher density electronics owing to reduced heat generation owing to reduced dissipation. However, if I recall comments here correctly we are getting to the point where electromagnetic shielding may be required as we scale down further which provides a second limiting factor to increased densities.

PS. Last year ETH Zurich also looked at weaving nanothreads in a kagome pattern, https://www.ethz.ch/en/news-and-events/eth-news/news/2017/08... ... note also that this style of weaving is widespread across all of continental Southeast Asia, at least southwest China, Vietnam, Philippines, Laos, Thailand, Malaysia, Myanmar and probably further west in South Asia. It is real a shame that a lot of terminology falls in to the "some random American saw a Japanese name for something so it is termed Japanese in English" category (eg. various food ingredients, philosophical concepts, art history, etc.). People could learn a lot more if they had broader regional comprehension of Asia and its history.

It isn't like those sorts of inaccuracies are unique to Asia. "Danish" pastries are called "Vienna bread" in Denmark because they weren't introduced to Denmark until an influx of foreign bakers caused by the Danish baker's union going on strike.

I bet they regretted that strike :)

The fact that the only thing I can contribute is 'this is really cool' is humbling/frustrating/limiting but really well done to this team.

If true and if cost effective to produce.

It won't be too long (decades, not centuries) until we have molecular nanotechnology that can build out human-scale devices atom-by-atom. But right now, as far as we know, room temperature superconductors don't exist, so even if it is difficult to produce now it is a monumental step forward if this were a room temperature superconductor.

Not quite. The paper cited above [0] Figure 2 pg 17 shows conductivity as a function of temperature. A superconductor has a flat part of the conductivity at low temperature here they have not reached it. There is no transition [1]. The do say on page 8 of [0]: "Extending this approach to stabilize the dispersionless states similarly expected from the kagome network adds an exciting prospect for increasing correlations and enabling the study of magnetically driven fractionalization of states" So it may be a possibility in the future.

[0] https://arxiv.org/abs/1709.10007 [1] https://en.wikipedia.org/wiki/Superconductivity

Thank you for finding the source. Looks like this was inaccurate / ambiguous reporting. Still a great discovery for what it is.

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