What if…we get high-temperature superconductors? Bindings of hope
Lossless transmission lines, low-temperature electrical engineering, superelectromagnets, finally gently compressing millions of degrees of plasma in thermonuclear reactors, a quiet and fast maglev rail. We have so many hopes for superconductors...
Superconductivity the material state of zero electrical resistance is called. This is achieved in some materials at very low temperatures. He discovered this quantum phenomenon Kamerling Onnes (1) in mercury, in 1911. Classical physics fails to describe it. In addition to zero resistance, another important feature of superconductors is push the magnetic field out of its volumethe so-called Meissner effect (in type I superconductors) or the focusing of the magnetic field into "vortices" (in type II superconductors).
Most superconductors only work at temperatures close to absolute zero. It is reported to be 0 Kelvin (-273,15 °C). The movement of atoms at this temperature it is almost non-existent. This is the key to superconductors. Normally electrons moving in the conductor collide with other vibrating atoms, causing energy loss and resistance. However, we know that superconductivity is possible at higher temperatures. Gradually, we are discovering materials that show this effect at a lower minus Celsius, and recently even at plus. However, this again is usually associated with the application of extremely high pressure. The biggest dream is to create this technology at room temperature without gigantic pressure.
The physical basis for the appearance of the state of superconductivity is formation of pairs of cargo grabbers - the so-called Cooper. Such pairs can arise as a result of the union of two electrons with similar energies. Fermi energy, i.e. the smallest energy by which the energy of a fermionic system will increase after the addition of one more element, even when the energy of the interaction binding them is very small. This changes the electrical properties of the material, since the single carriers are fermions and the pairs are bosons.
Cooperate therefore, it is a system of two fermions (for example, electrons) interacting with each other through vibrations of the crystal lattice, called phonons. The phenomenon has been described Leona cooperates in 1956 and is part of the BCS theory of low-temperature superconductivity. The fermions that make up the Cooper pair have half spins (which are directed in opposite directions), but the resulting spin of the system is full, that is, the Cooper pair is a boson.
Superconductors at certain temperatures are some elements, for example, cadmium, tin, aluminum, iridium, platinum, others pass into the state of superconductivity only at very high pressure (for example, oxygen, phosphorus, sulfur, germanium, lithium) or in the form of thin layers (tungsten , beryllium, chromium), and some may not yet be superconducting, such as silver, copper, gold, noble gases, hydrogen, although gold, silver and copper are among the best conductors at room temperature.
"High temperature" still requires very low temperatures
In 1964 year William A. Little suggested the possibility of the existence of high-temperature superconductivity in organic polymers. This proposal is based on exciton-mediated electron pairing as opposed to phonon-mediated pairing in BCS theory. The term "high temperature superconductors" has been used to describe a new family of perovskite-structured ceramics discovered by Johannes G. Bednorz and C.A. Müller in 1986, for which they received the Nobel Prize. These new ceramic superconductors (2) were made from copper and oxygen mixed with other elements such as lanthanum, barium and bismuth.
2. Ceramic plate hovering over powerful magnets
From our point of view, "high-temperature" superconductivity was still very low. For normal pressures, the limit was -140°C, and even such superconductors were called "high-temperature". The superconductivity temperature of -70°C for hydrogen sulfide has been reached at extremely high pressures. However, high-temperature superconductors require relatively cheap liquid nitrogen for cooling, rather than liquid helium, which is essential.
On the other hand, it is mostly brittle ceramic, not very practical for use in electrical systems.
Scientists still believe that there is a better option waiting to be discovered, a wonderful new material that will meet criteria such as superconductivity at room temperatureaffordable and practical to use. Some research has focused on copper, a complex crystal that contains layers of copper and oxygen atoms. Research continues on some anomalous but scientifically unexplained reports that water-soaked graphite can act as a superconductor at room temperature.
Recent years have been a veritable stream of "revolutions", "breakthroughs" and "new chapters" in the field of superconductivity at higher temperatures. In October 2020, superconductivity at room temperature (at 15°C) was reported in carbon disulfide hydride (3), however, at very high pressure (267 GPa) generated by the green laser. The Holy Grail, which would be a relatively cheap material that would be superconductive at room temperature and normal pressure, has yet to be found.
3. Carbon-based material that is superconductive at 15°C.
Dawn of the Magnetic Age
The enumeration of possible applications of high-temperature superconductors can begin with electronics and computers, logic devices, memory elements, switches and connections, generators, amplifiers, particle accelerators. Next on the list: highly sensitive devices for measuring magnetic fields, voltages or currents, magnets for MRI medical devices, magnetic energy storage devices, levitating bullet trains, engines, generators, transformers and power lines. The main advantages of these dream superconducting devices will be low power dissipation, high speed operation and extreme sensitivity.
for superconductors. There is a reason why power plants are often built near busy cities. Even 30 percent. created by them Electric energy it may be lost on transmission lines. This is a common problem with electrical appliances. Most of the energy goes to heat. Therefore, a significant portion of the computer surface is devoted to cooling parts that help dissipate the heat generated by the circuits.
Superconductors solve the problem of energy losses for heat. As part of experiments, scientists, for example, manage to earn a living electric current inside the superconducting ring over two years. And this is without additional energy.
The only reason the current stopped was because there was no access to liquid helium, not because the current could not continue to flow. Our experiments lead us to believe that currents in superconducting materials can flow for hundreds of thousands of years, if not more. Electric current in superconductors can flow forever, transferring energy for free.
в no resistance a huge current could flow through the superconducting wire, which in turn generated magnetic fields of incredible power. They can be used to levitate maglev trains (4), which can already reach speeds of up to 600 km/h and are based on superconducting magnets. Or use them in power plants, replacing traditional methods in which turbines spin in magnetic fields to generate electricity. Powerful superconducting magnets could help control the fusion reaction. A superconducting wire can act as an ideal energy storage device, rather than a battery, and the potential in the system will be preserved for a thousand and a million years.
In quantum computers, you can flow clockwise or counterclockwise in a superconductor. Ship and car engines would be ten times smaller than they are today, and expensive medical diagnostic MRI machines would fit in the palm of your hand. Collected from farms in the vast desert deserts around the world, solar energy can be stored and transferred without any loss.
4. Japanese maglev train
According to the physicist and famous popularizer of science, Kakutechnologies such as superconductors will usher in a new era. If we were still living in the era of electricity, superconductors at room temperature would bring with them the era of magnetism.
