Weizmann Institute scientists have managed to explain how superconductors penetrated by magnetic fields 'remember' the physical properties of electrical currents. A superconductor is a substance capable of conducting electricity without any resistance. Superconductors may prove pivotal for developing a variety of communication, industry, and transportation technologies, including conducting electric currents across vast distances. A considerable number of these innovations are based on the controlled exposure of superconductors to magnetic fields, and the manner in which these fields penetrate the superconductor.
The magnetic fields infiltrate some of the superconductors in the form of tiny whirlpools, each containing a weak magnetic flux at its core. Under optimal conditions, these whirlpools settle at equal distances from each other, in a fashion similar to the arrangement of molecules within a solid crystal. However, Prof. Eli Zeldov of the Weizmann Institute's Department of Condensed Matter Physics, has previously proven that under certain conditions this 'crystal' may undergo a 'meltdown' so that the whirlpools are transformed to a disorganized state resembling the material's liquid structure. An electric current passing through a superconductor may affect the motion of the magnetic whirlpools, thereby impairing conductivity.
In a paper recently published in Nature, Prof. Zeldov, his research student Yosef Paltiel, and their colleagues explain how these whirlpools enable the superconductor to 'remember' the properties of currents that passed through it (for example: their strength, direction, and course). The scientists conducted a series of experiments that led them to conclude that the electric current leaves its mark on the magnetic whirlpools, forming them into lasting patterns. Essentially a 'story of currents gone by,' these patterns provide information regarding the physical properties of currents that had previously infiltrated the superconductors.
The enhanced understanding of superconductors generated by this research may lead to the development of advanced superconductor devices.
This research was funded by the Robert and Giampiero Alhadeff Research Award, Greece.
Prof. Eli Zeldov holds the David and Inez Myers Chair of Condensed Matter Physics.
The Weizmann Institute of Science is a major center of scientific research and graduate study located in Rehovot, Israel.