Physicists Discover a 'Family' of Robust, Superconducting Graphene Structures (phys.org) 44
In 2018, MIT researchers found that if two graphene layers are stacked at a very specific "magic" angle, the twisted bilayer structure could exhibit robust superconductivity, a widely sought material state in which an electrical current can flow through with zero energy loss. Now the team reports that [...] four and five graphene layers can be twisted and stacked at new magic angles to elicit robust superconductivity at low temperatures. Phys.Org reports: This latest discovery, published this week in Nature Materials, establishes the various twisted and stacked configurations of graphene as the first known "family" of multilayer magic-angle superconductors. The team also identified similarities and differences between graphene family members. The findings could serve as a blueprint for designing practical, room-temperature superconductors. If the properties among family members could be replicated in other, naturally conductive materials, they could be harnessed, for instance, to deliver electricity without dissipation or build magnetically levitating trains that run without friction.
In the current study, the team looked to level up the number of graphene layers. They fabricated two new structures, made from four and five graphene layers, respectively. Each structure is stacked alternately, similar to the shifted cheese sandwich of twisted trilayer graphene. The team kept the structures in a refrigerator below 1 kelvin (about -273 degrees Celsius), ran electrical current through each structure, and measured the output under various conditions, similar to tests for their bilayer and trilayer systems. Overall, they found that both four- and five-layer twisted graphene also exhibit robust superconductivity and a flat band. The structures also shared other similarities with their three-layer counterpart, such as their response under a magnetic field of varying strength, angle, and orientation.
These experiments showed that twisted graphene structures could be considered a new family, or class of common superconducting materials. The experiments also suggested there may be a black sheep in the family: The original twisted bilayer structure, while sharing key properties, also showed subtle differences from its siblings. For instance, the group's previous experiments showed the structure's superconductivity broke down under lower magnetic fields and was more uneven as the field rotated, compared to its multilayer siblings. The team carried out simulations of each structure type, seeking an explanation for the differences between family members. They concluded that the fact that twisted bilayer graphene's superconductivity dies out under certain magnetic conditions is simply because all of its physical layers exist in a "nonmirrored" form within the structure. In other words, there are no two layers in the structure that are mirror opposites of each other, whereas graphene's multilayer siblings exhibit some sort of mirror symmetry. These findings suggest that the mechanism driving electrons to flow in a robust superconductive state is the same across the twisted graphene family.
In the current study, the team looked to level up the number of graphene layers. They fabricated two new structures, made from four and five graphene layers, respectively. Each structure is stacked alternately, similar to the shifted cheese sandwich of twisted trilayer graphene. The team kept the structures in a refrigerator below 1 kelvin (about -273 degrees Celsius), ran electrical current through each structure, and measured the output under various conditions, similar to tests for their bilayer and trilayer systems. Overall, they found that both four- and five-layer twisted graphene also exhibit robust superconductivity and a flat band. The structures also shared other similarities with their three-layer counterpart, such as their response under a magnetic field of varying strength, angle, and orientation.
These experiments showed that twisted graphene structures could be considered a new family, or class of common superconducting materials. The experiments also suggested there may be a black sheep in the family: The original twisted bilayer structure, while sharing key properties, also showed subtle differences from its siblings. For instance, the group's previous experiments showed the structure's superconductivity broke down under lower magnetic fields and was more uneven as the field rotated, compared to its multilayer siblings. The team carried out simulations of each structure type, seeking an explanation for the differences between family members. They concluded that the fact that twisted bilayer graphene's superconductivity dies out under certain magnetic conditions is simply because all of its physical layers exist in a "nonmirrored" form within the structure. In other words, there are no two layers in the structure that are mirror opposites of each other, whereas graphene's multilayer siblings exhibit some sort of mirror symmetry. These findings suggest that the mechanism driving electrons to flow in a robust superconductive state is the same across the twisted graphene family.
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Your mom was a robust, superconducting graphene structure.
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There are a bunch of graphene products available, from tennis rackets to fishing rods. You can buy a pair of headphones from Anker with graphene drivers for seventy bucks.
Nothing interesting (Score:5, Interesting)
Y-Ba-Cu-O, on the other hand is considered high temperature. Around that liquid nitrogen, 77k. This is a sought after temperature as nitrogen is easy to, liquify, and use.
This room temperature claim here sounds like a standard tag that one puts in papers so that one can ask for more research grants for more research. The ones we used to put in was that the military applications were substantial. But I see no theoretical basis that these operate above freezing, much less 300K. As far I know all room temperate superconductors require impractical pressures for widespread use.
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This room temperature claim
There is no "room temperature claim".
The statement is: at low temperature. And even in the summary they make clear they are talking about close to absolute zero.
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Not when you're talking cryogenics it isn't.
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Sure we "need" those. But you sound like a guy who does not differentiate between need and want.
We want super cool (oops wrong word) high temperature super conductors. But: we do not really need them.
The research above is about how to be able - by material science - to construct a fibre/thing that is super conducting.
If you are against science: then don't post here on /.
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Hey, why stop there? Let's just invent zero point modules like on Stargate and just install one wherever you need it. Superconductors and nuclear power plants! Lol primitive!
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Low temperature is 77k
That would be high temperature super conducting, the holy grail of the current field of science.
Low is what the word low mean: low
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Re: Nothing interesting (Score:3)
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ye but this is at much much more cooler temps... o wait
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But we do not really know "how they work".
So if one is able to craft a new super conductor on demand, we might figure out how they work.
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We do, but they're ceramics, which means they're a pain in the ass to make into pretty much anything we want to use them for. Also, we're never happy, so we'd like them to work another 120 K or so higher, please.
We have room temperature super conductors (require high pressure), high temperature, low pressure (ceramic), and metal (low temperature). We'd like to get something that doesn't have any parentheses.
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Mercury is
Not pure copper
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i am pretty sure "shit" is super conductive at those temps. /.
look out for my new article on
Re: Nothing interesting (Score:1)
Re: Nothing interesting (Score:1)
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WOW you are new here!
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That's the superconducting part. However this research group does seem to be making progress:
Here we report the experimental realization of superconducting magic-angle twisted four-layer and five-layer graphene
My question would be whether making these twisted 4/5 layers of graphene does something useful besides the superconducting.
YBCOh be-jeezus is it fragile (Score:2)
5 atomic layers down⦠(Score:2)
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Because it helps science get one step closer to fusion and flying cars!
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the funding must flow
Music to your ears! (Score:1)
Like you’ve never heard before.
In 2008 an olde Hammond B3 came onto the chopping block. Its owner frustrated, he took a hammer to its keyboard. Hooked up to its Leslie speaker, the pair had been married, paired together since 1954. It sounded magnificent!
But then it turned to shit (aka normal) organ tone and timbre. Something changedelucidating the feeling of betrayal and damage by its owner. A rare ebony B3 it had never toured or left in direct sunlight faded finish.
The Hammond shop explained that th
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That'd be cool. Like really cool. Like I'm-not-sure-how-long-you'd-survive-listening-to-music-in-1-Kelvin cool.
Preprint (Score:2)
Yawn (Score:1)
Who cares besides physicsists? Call me when you have some material that can superconduct beyond 200k
Re:Yawn (Score:4, Insightful)
You're probably reading the wrong site. You might be looking for amazon.com or maybe walmart.com.
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Um, no. Multiple graphene stacks would be impossible to build on a commerical scale. Also we already have superconductors that work at much higher temperatures that are much easier to build.
Who the fuck even cares? (Score:2)
Mass production of graphene still not a thing (Score:1)
Aren't we still struggling to mass produce graphene, let alone at reasonable cost (once scaled, sure - but, still...)??
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