Slovak and Spanish scientists have created an “invisibility cloak” from cylindrical layers of a superconductor and a ferromagnet, the combination of which makes it possible to hide an arbitrary object from a magnetic field, RIA Novosti reports , citing a publication in the journal Science .

Over the past decade, physicists have developed several devices that make it possible to hide a particular object from electromagnetic radiation in a narrow frequency range. Thus, in 2009, American physicists created a silicon coating that makes an object invisible in the infrared frequency range. In 2010, the first three-dimensional “stealth” cloak was created; in 2011, scientists learned to hide objects from the passage of time, and already this year - from microwave radiation.

A team of physicists led by Alvaro Sanchez from the Autonomous University of Barcelona has developed a technology that can hide a three-dimensional object of arbitrary shape from the magnetic field generated by natural magnets or direct current.

Sanchez and his colleagues experimented with metamaterials and other exotic forms of matter and found that a fairly simple combination of a superconductor and a ferromagnet had the necessary stealth properties.

As scientists explain, superconductors have special magnetic properties and do not allow a magnetic field to pass through them. However, they cannot be used as a magnetic “stealth” coating - superconductors distort field lines close to them, and such a “cloak” can be detected by this interference.

The authors of the article were able to overcome this problem using a tandem of a superconductor cylinder and a ferromagnetic layer covering it. According to the researchers, ferromagnets are a kind of antipode to superconductors - they attract magnetic field lines rather than repel them. Precisely selected thickness of the ferromagnetic layer makes it possible to neutralize the distortion of field lines that arise due to the action of the superconductor.

Scientists put their ideas into practice by assembling a magnetic “invisibility cloak” from several ribbons of high-temperature superconductor glued to a cylinder made of an alloy of iron, chromium and nickel. Physicists cooled their invention to 77 degrees Kelvin (minus 196 degrees Celsius), placed it in the field of two permanent magnets and measured the strength of the magnetic field inside the device.

The “invisibility” cloak performed very well - it suppressed the magnetic field not only within the device itself, but even beyond its borders.

Sanchez and his colleagues believe that their invention could be used for magnetic shielding of sensitive scientific instruments. The absence of size restrictions and industrially available materials make it possible to produce and use such “cloaks” now, the researchers conclude.

An invisibility cloak was created from a superconductor and a ferromagnet - Gazeta.Ru