Physicists from Russia filmed «escape» magnetic vortices from the superconductor

© Photo : Elena Havin/ press service Emptively vortex at the boundary between a superconductor and a normal metalPhysicists from Russia filmed «escape» magnetic vortices from the superconductor© Photo : Helen Havin/ press service Ftpaddress to daily updates RIA Science

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. Russian scientists found that the magnetic «funnel» that exist in certain superconductors, unable to escape from them and to penetrate the «common metals», which gives them an unusual quantum properties. Their findings and pictures of «escape» was published in the journal Nature Communications.

«Similar experiments were made possible by the progress in the field of scanning tunneling microscopy. We were able to work confidently at ultralow temperatures and ultrahigh vacuum conditions, so that the surface of the superconductor and the metal remained «nuclear is clean» for a long time. This microscope is in MIPT in our laboratory,» — says Vasyl Stolyarov, a physicist from Dolgoprudny, whose word brings the press service of the University.

All superconductors have unusual property that they «don’t like» magnetic field and seek to push out in that case, if the line of this field in contact with them. If the field strength exceeds a certain value, then the superconductor loses properties and becomes a «normal» material.

This phenomenon, which physicists called the Meissner effect works differently in different superconductors. In superconductors of the first kind, the magnetic field can not exist in principle, but in their «fellow» of the second kind, the magnetic field can penetrate a small distance in those places where the combination of superconducting and non-superconducting properties.

This phenomenon was opened in 1957, the Soviet physicist Alexei Abrikosov, for which he and Vitaly Ginzburg and Anthony Leggett received the 2003 Nobel prize in physics. The same phenomenon of «partial penetration» of the magnetic fields inside the superconductor generates a special magnetic «funnel» circular electric currents, which scientists today call the «Abrikosov vortices».

The quantum nature of these vortices and their stability and predictability has long attracted the attention of physicists trying to build quantum computers or light and in need of reliable and fast storage devices that are able to work directly with such computing devices.

It tells the carpenters, physicists have long been interested in whether such magnetic funnels exist in other materials that are part of the quantum properties of superconductors in contact with him. Is, for example, occurs, if you connect the plate of niobium, acquires superconducting properties at a temperature of 4-5 degrees above absolute zero, with a film of copper cannot become superconductor in such conditions.

To learn it is quite difficult, as the Abrikosov vortices, some of the fastest objects in the Universe, it is extremely difficult to «catch» and study. Russian scientists were able to solve the problem using extremely sensitive tunneling microscope, which they «fired» a sandwich of copper and niobium by electron beams, and new theories that allowed them to find traces of a similar quantum of craters in images from the microscope.

Watching electrons in this structure were repelled by passing through them a stream of electrons, the scientists were able to find the «sockets» magnetic funnels, «runaway» plate of copper. They were exactly on those points where their «base» in the thickness of the superconductor, and thus they penetrated at an unexpectedly large distance into the normal metal, a few tens of nanometers.

Their discovery, as noted by carpenters, says that such «sandwiches» can be used as elements of a quantum computer, and hybrid quantum devices, where necessary to combine the properties of conventional superconducting metals and their «cousins». To do this, however, requires further observation «shoots» quantum funnels of superconductors, the scientists conclude.