Scientists Jacobo Santamaria and Carlos Leon Group Complex Materials Physics, University Complutense of Madrid (UCM), Spain, in collaboration with the Mixed Unit for Physics CNRS-Thales in Palaiseau (France) have found evidence of supercurrents existence of spin-polarized.
Spin is a quantum property of electrons, with no analog in a classical description, and since its discovery in the early twentieth century has allowed understanding the electronic behavior of materials. The spin of an electron can take only two well-defined values that are assigned to opposite directions in space (above and below).
The study, published in the journal Nature Physics, illustrates the possibility of generating spin polarized supercurrents in artificial nanostructured materials based on complex oxides in a new scenario that can be understood as the “union” of two fields, spintronics and superconductivity mesoscopic. These effects may have applications in various fronts that go from new spintronic devices to quantum computing.
Samples produced in Madrid within the CIS Excellence Moncloa Campus UCM-UPM are complex oxide heterostructures that combine ferromagnetic and high-temperature superconductors, and have been measured in Paris. The appearance of an interference phenomenon of the electronic states is known as ‘McMillan-Rowell resonance’ proof that the current in the ferromagnetic superconductor persists despite theoretically antagonistic character.
Ferromagnetism is a phenomenon that results from a macroscopic manifestation of a quantum state of the electrons of a metal in which their spins are arranged parallel to each other (all up or all down). If a current is injected through a ferromagnetic contact it will have their spins parallel, and is said to be polarized.
Incorporating these materials into electronic devices has led to spintronics, which exploits the properties of the spin in the same way that exploits the electronics of the electric charge. This field has experienced a breakthrough in the last decade and is thought to lead to considerably more efficient than current and represent an alternative to silicon-based technology.
Moreover, superconductivity is antagonistic state of matter to the above in which the electrons are paired and have their spins are antiparallel. Superconductive materials are capable of carrying electric currents without energy consumption, so that it was considered possible application for the transport of electricity or for ultrafast electronic devices.
In recent years there has been a great effort on the combination of both phenomena on the basis of the applications that might result from the ability to propagate over long distances superconducting current spin polarization.