New Graphene Discovery May Unlock Superconductivity secrets

[ Music, ], hello, everyone subject: zero graphene has done it again. Folks in a paper published back in March, 2019 in scientists announced yet another curious characteristics of graphene, but before we dive into this, let's recap some of the super conductivity findings of graphene. All of this started back in 2005 when they first noticed that Griffin had some weird properties for those of us who have been waiting for graphene. For that long, I would like to point out that that famous and nonnamous quote graphene can do everything but leave the lab is not true anymore. There are actually products already available out there, and you should look for my video, the current state of graphene, where I talk about of some of the products. There are already available going back to superconductivity. Since 2005, scientists have known about this superconductivity property of graphene when mixed with other known elements such as calcium, copper and lithium, just to name a few, but at that time they used what they called intercalated bilayer of graphene, which would look something like this. This is a calcium, graphene sandwich and, basically, what it does is. It allows the electrons to move more freely due to the properties of calcium and graphene turn into a superconductor. But then again, they still rely on the fact that they had to turn the temperature way down for the effect to appear or about two to four kelvins, to be more precise for those of you that might not know the best online source of knowledge. Wikipedia generally defines superconductors as it is a phenomenon of exactly zero. Electrical resistance and expulsion of magnetic reflects fields occurring in a certain materials called superconductors when cooled below a characteristical critical temperature. Essentially, for you to reach that state, you have to use certain materials at nearly zero Kelvin, which makes it impossible in everyday use and for the longest time scientists have been looking for other ways to achieve this phenomenon with many compounds, including, but not limited to notice. That the temperatures used are all near zero Kelvin, which can only be achieved in a lab for very specific applications. But the key aspect of superconductors is that the transport electrons at zero electrical resistance, which would be optimal for many things like MRI particle acceleration electrical transmissions. Among many other technologies that would appear overnight in a sort of electrical revolution 2.0, the problem is every frame would have to be cooled down to nearly zero Kelvin, which makes it impractical for any day-to-day application and has remained the biggest challenge for more than three decades And then there is the fact that superconductors are generally placed into two categories: conventional and unconventional, where conventional is something that can be explained by mainstream theory, whereas unconventional can't that's simple and graphene, my dear viewers fall into the second one. Nevertheless, in 2018, scientists may have found the answer, and all they needed to do was put two graphene sheets on top of each other and rotate one of them at exactly one point, one degrees - and I mean exactly here because if you move a little more just Like point one degree and the opposite effect is seen, but how did I even get to this? Well, the MIT group led by Pablo Jerry Leo O'Hara, we're looking into the magic angle effect, which is a theory to which, by changing the angle of a material that is aligned against each other, may have interesting outcomes to be more clear. This wasn't something out of the blue or some lucky research. Finding this effect has been theorized for many years, where it predicted that any 2d materials at a specific angle twist would have its property change, but nobody knew for certain what would happen. So this is not exclusive to graphene, as in theory, you could do this to any element. It so happens that graphene is made out of carbon which, as we will see later made scientists not expect anything like this, and this is why scientists are baffled with this new discovery. Simply because having a superconductor made out of carbon makes all kinds of sense and you may open the doors for many more interesting things to come. So most of the theories and understandings gathered over the years cannot be used to explain this one, but what they know is that graphene is able to reach the same states as conventional superconductors with just 110 thousand of the electron density. This is important because before this, it was thought that the electron density was a key factor at play in superconductivity. Hence why a lot of superconductors were made using copper and other materials. The hypothesis is that electrons reach a vibrational state that pairs them up with each other stabilizing a path and allowing them to move without resistance, but with graphene. This is not the case since the electron density is many times lower, which suggests that whatever is happening with graphene is many more times stronger than conventional superconductors. But then again, scientists aren't really agreeing with how electrons interact with unconventional superconductors, as they still don't know. What make electrons pair up in the first place, scientists now have the opportunity to create devices to which will be easier to study than Cup rates, remembering that Cup rates often have to be subjected to precise mixing of elements and treated at extreme magnetic fields. On the other hand, graphene is cheaper easier to make well it's getting easier and require way less preparation where all they have to do is change the sheet angle and play with electrical fields in order to yield the same results, easy peasy, lemon squeezy. These graphene experiments started with the exploration of the magic angle effect where all they were looking for is, if anything odd would happen and what they found was a bit mesmerizing. What they found out quickly was that, at the angle of 1.1 degrees, a slight offset that is hard to get it created, what they called a precise mori configuration, which is what I talked about earlier when I mentioned the magic theory angle. Amoy pattern is nothing but a pattern that interferes with each other like two sheets of parallel lines that are rotated on top of each other with graphene due to its hexagonal pattern. This creates interesting visuals, while in the molecular level it may result in weird behavior the configuration at that specific angle created a strong interaction in between electrons and the graphene sheet. Any other angle, and nothing happens initially. They discovered that, when twisted at that angle, the graphene sheets would show behavior of what is described as a Mott insulator. Mod insulators are nothing but materials. That, in theory, should conduct electricity, but in fact, and I'm not doing so, creating an insulation effect, particularly at low temperatures. In theory, an insulator is any mature that which its last band gap is filled with electrons, therefore, making it hard for electrons to move freely with mod insulators. That is what was expected to happen, but because of a strong electrostatic interactions between electrons exist, the material ceases. Any electricity flow, so it all comes down to this. The idea here is that they created materials that they expected to behave in a certain way, but when tested, they found the opposite, which goes against the conventional band theory, in this case with graphene. It turned out that at that angle, whenever they measured the conductivity and the density of particles, it suggested that at this angle, graphene was behaving like a ma insulator to see if the effects would be the same at any voltage, they increased the electrical field to pump Up just a few extra charges into the sheets, and that is when graphene became a superconductor. The important thing here is that every experiment afterwards confirmed that this was in fact happening not only at MIT, but also in Harvard and other universities. Now, although this is pretty cool, they still have one problem and it all comes down to keeping the two graphene layers at that angle. Just to give you an idea, graphite layers are usually aligned at the same direction so to twist the layers is still a challenge, and then there is the fact that any small perturbation in the model either by electricity or heat and the two layers will go back To normal, so you can expect the test in this effect has been quite difficult, but all of this raises the question: if this is superconductivity at all happening in this material up till now, scientists aren't sure if this is the case, but so far experiments are positive And can only confirm that there are unusual things going on with manipulating the graphene sheet angle. Nevertheless, we can expect more cool things to come about graphene, as it's proving itself to be, indeed, a wonder material, alright, folks, that's it we're done here. [, Music, ],