Superconductors can be called one of the most interesting and amazing materials in nature. Beyond any logical discussion of quantum-mechanical effects lead to the fact that the superconductors below the critical temperature completely disappears in the electrical resistance. One of this property is enough to spark the imagination. Current that can flow continuously without losing any energy, means a transmission of energy with virtually no loss in the cables. When renewable energy starts to dominate in network and high-voltage transmission across continents will be continuous cables without losses will lead to significant savings.
Moreover, the superconducting wire carrying current without loss, will be an excellent store of energy. Unlike batteries, which eventually deteriorate, if the resistance is really zero, it will be possible to find a superconductor in a billion years and find that it flows the same current. Energy could be stored indefinitely!
In the absence of resistance through the superconducting wire, it would be possible to pass a powerful current and to the magnetic field of incredible power.
They could be used for levitating trains and incredible acceleration, transforming the entire transport system. Could be used in power plants, replacing the conventional methods that rotate the turbine in a magnetic field to generate electricity, and in quantum computers in which zeros and ones (normal bits) is replaced with the current clockwise or counterclockwise current in the superconductor.
Arthur C. Clarke once said that sufficiently advanced technology is indistinguishable from magic; superconductors definitely like a magical device. Why do they still not changed our world? The problem is the critical temperature.
Most of these materials the critical temperature is hundreds of degrees below freezing. From superconductors also have a critical magnetic field outside the magnetic field of a certain intensity they no longer work. It turned out that materials with internal high critical temperature and often offer the most powerful magnetic field when cooled significantly below this temperature.
This means that the use of superconductors has so far been limited to situations where you can afford cooling of the components to a temperature of almost absolute zero: the particle accelerators and experimental reactors of nuclear fusion, for example.
But even if some aspects of superconducting technologies restrict them in the use of high-temperature superconductors, the search continues. Many physicists still believe that the superconductors working at room temperature, may exist. And such a discovery would pave the way incredible new technologies.
In the search for superconductors that work at room temperature
After Heike kamerlingh Onnes accidentally discovered superconductivity, trying to prove the theory of Lord Kelvin that the resistance will increase as the temperature decreases, theorists trying to explain the new property in the hope that his understanding will enable us to create superconductors that work at room temperature.
So there was the BCS theory (Bardeen, Cooper, sniffer), which explains some of the properties of superconductors. It was also predicted that the dream of technologists, superconductors at room temperature may not be feasible; the maximum temperature of superconductivity according to BCS theory, it was only 30 degrees above absolute zero.
In the 1980’s, everything changed, thanks to the discovery of unusual high-temperature superconductivity. “High temperature” is still very cool: the highest temperature for superconductivity amounted to -70 degrees to hydrogen sulfide at extremely high pressure. At normal pressure, the upper limit is -140 degrees. Unfortunately, high-temperature superconductors, which require relatively cheap liquid nitrogen instead of liquid helium for cooling is mostly brittle ceramics that is extremely difficult to turn into wire and apply in practice.
Considering the limitations of high-temperature superconductors, scientists continue to believe that there is a better option awaiting discovery — an incredible new material that will make superconductivity affordable, practical, and most importantly — working at room temperature.
Without a detailed theoretical understanding of this phenomenon — although substantial progress is being made constantly — sometimes scientists feel that they are doing a guesswork trying to find suitable materials. It’s like trying to guess the phone number that is composed of periodic table elements instead of numbers. But the prospect remains very concerned. The Nobel prize and a brave new world of energy and electricity — not a bad reward for a successful result.
Some studies focus on cuprates, complex crystals that contain layers of copper and oxygen atoms. Connection cuprates with different elements, exotic compounds like mercury-barium-calcium-copper oxide, create the best superconductors known today.
Scientists also continue to report anomalous and unexpected news that the water-soaked graphite can act as the superconductor, operating at room temperature, but there are no signs that this news can be put in the basis of technology.
In early 2017, exploring the most extreme and exotic forms of matter that we can create on Earth, the scientists managed to compress the hydrogen to the metal state. For that they needed a pressure greater than the pressure in the core of the Earth and is thousands of times greater than at the bottom of the ocean. Some scientists in this field — physics of condensed matter — at all doubt that metallic hydrogen was able to produce.
However, it is believed that metallic hydrogen may be a superconductor, working at room temperature. But working with samples is very difficult, because even diamonds containing metallic hydrogen, can not withstand a catastrophic pressure.
Superconductivity — or behavior, greatly resembling, were also observed in the yttrium-barium-copper oxide at room temperature in 2014. The only problem is that electron transport was held only a tiny fraction of a second and demanded the bombardment of the material by laser pulses.
Not very practical — Yes. Interesting — of course!
And other new materials exhibit interesting properties. Nobel prize in physics in 2016 was awarded for theoretical work that characterizes topological insulators — materials exhibiting similar strange quantum behavior. They can be considered perfect insulators, the total mass of the material, but an unusually good superconductors in a thin layer on the surface.
Microsoft relies on topological insulators as a key component of a quantum computer. Also they are considered as potentially important components of the miniature circuits.
Some notable properties of electron transport was also observed in the new “two-dimensional” structures, like graphene, but of other elements. These are materials with a thickness of one atom or molecule.
Superconductivity at room temperature remains elusive and exciting, and which was for over a century. It is unclear whether it may be a superconductor, operating at room temperature, but the discovery of high temperature superconductors is a promising indication that an unusual and very useful quantum effects can be found unexpectedly.
Perhaps in the future — with the help of artificial intelligence or discoveries of camerlingo-onesof the 21st century, these technologies will become indistinguishable from magic.