Impossible superconductors gone live: Lomonosov Moscow State University physicists managed to directly measure the 'impossible' superconductors' gaps the first in the world

A team of Russian scientists lead by the Lomonosov Moscow State University physicists for the first time in history managed to measure, reliably and directly, the energetic gaps of a number of superconductors (first of all -- iron-containing). According to Svetoslav Kuzmichev who leads the research project the results of the work would allow to solve some questions concerning the appearance of the superconductivity in the iron-containing materials.

The main thing interesting for the physicists in this experiment was a chance to measure the temperature dependences of the two energetic gaps. The term "superconducting gap" refers to denoting a range of energies that is forbidden for the conducting electrons.

Since 1957, when American physicists John Bardeen, Leon N. Cooper and John Robert Schrieffer developed a theory explaining the superconductivity phenomena (the BCS theory, awarded with the Nobel Prize in 1972), there was only one such band: from the temperature of the transition to the superconductivity state to zero. But in 1959 a probable existence of the two-gap superconductors was assumed by a Soviet physicist V.A. Moskalenko and his US colleague G. Suhl. The two scientists independently deriveded sets of equations, describing mechanisms of such superconductivity, however experimentally the first two-band superconductor was found only at the beginning of the present century, in 2001. It was quite a simple in composition magnesium diboride.

By that time physicists doubted the possibility of the two-gap superconductivity. Something new, standing out of the common frameworks, always appears as a heavy psychological burden for researchers of any scientific fields. To lighten this 'burden', the scientific community preoccupied with superconductivity problems treated magnesium diboride as in exception, confirming the rule.