“The study of matter in unusual States” – so formulated the achievement in physics, earned in 2016 Nobel prize. The winners of physics David Towles from the University of Washington, Duncan Haldane of Princeton and Michael Kosterlitz of brown University who developed the science of topological phase transitions, i.e. a change of state of a substance as a result of external influences.
The merit of the above mentioned scientists is that they have developed mathematical methods to describe the unusual phases and properties of matter, such as superconductors, superfluids, and magnetic tapes.
In order to understand the importance of the work of the laureates, have little insight into the history of superconductivity – the phenomenon, manifested in many chemical elements and alloys when cooled below a certain temperature. Namely, they move to the state in which their electrical resistance to direct current is completely absent. This phenomenon was discovered in 1908 and produced a real revolution in science, because:
– at very low temperatures the current is carried in superconductors with virtually no loss, and therefore, it can be used in the creation of various switching devices, devices for temperature measurement and other devices of new generation;
they are ideal for creating electromagnets, in which doctors get MRI’s to study high-quality images of tissues of the internal organs in the cut without injury to the body;
on the basis of sverhprovodimost you can create a train on a magnetic “cushion” that seems to be flying over the rails.
There are a dozen technical innovations, which are based on the theory of superconductivity. However, until the end of the 70 years, scientists were convinced that it is possible only in three-dimensional substances, and can not appear in two-dimensional systems, for example, in conventional films.
Revolution in this issue made in the late 70-ies of Vadim Berezinsky — our physics at the Institute for theoretical physics. Landau – says Professor of the physical faculty of Moscow state University, head of the scientific group of the Russian quantum center, chief researcher, Institute of automation, Professor, RAS Alexey Rubtsov. He showed that the superconductivity in films still exists, but differs from superconductivity in three-dimensional samples. A fundamental role is played by the so-called vortices, which appear in films in a state of superconductivity. This work was later continued by Kosterlitz and Tulessa, who received the Nobel prize in physics in 2016. Berezinsky , alas, died, and not waiting for this event, in 1980.
Read the story “the Nobel prize today could be a Russian physicist”
– You can elaborate on the vortices in the films and how they are connected with the topological transition?
– The vortex is an inner current that arises in the film when cooled to a state of superconductivity, a kind of stable construction, which does not disappear by itself. Resistance this just linked to the topology (properties of substances are changed abruptly). Give an example of a rubber chamber: as much as you want to knead it, but still a hole inside, not going anywhere. Similarly, with the vortex — you can influence them in anything: to stretch the film in, attach some of the field, but he will still remain because it has a topological charge. The vortex can also provide a topological defect.
In subsequent years, the topology sounded even louder. To Thouless-Kosterlitz joined Haldane, who was engaged in another system, but is also associated with the topology.
– Why in due time Berezinsky not received a well-deserved award?
– First of all, because he died very quickly, in just a few years after opening. Secondly, the award was only now, when it became clear that the topology is very important. It should be noted that when the Berezinsky published his work on mathematical techniques for describing the unusual phases of matter in the “Journal of experimental and theoretical physics”, it is almost never understood. It is a difficulty even to publish did not want. But then it still missed, and in the West made a transfer… by the Way, a topological transition is now called “Berezinsky-Kosterlitz -Thouless”.
– All the concepts that we are now discussing relate to quantum physics. Where are they, in your opinion, can “to shoot” in the near future?
– It is believed that topological States are stable, protected from external influences. So, this security could do a good job of quantum computers (whose speakers are terribly unstable — decoherent). If scientists were able to come up with a topologically protected quantum information carriers, it would have led to a radical increase in the range and efficiency of quantum networks and cryptography, to new devices processing quantum information.