The superconducting spin valve and triplet superconductivity

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This project is oriented on the experimental investigation of the superconducting triplet components arising in superconducting spin valve system ferromagnet/ferromagnet/ superconductor (F/F/S). The main goal of this work is to explore new effects caused by the interplay between superconductivity and ferromagnetism in F/F/S heterostructures. The novelty of this work is dictated by (i) the value of the fundamental knowledge regarding newly discovered triplet superconducting components in fabricated S/F structures and (ii) their possible application in spintronics as logical elements, valves etc. The classical methods which I propose to apply in this modern physics area can serve as a reliable source of experimental data: Ultra high vacuum (UHV) deposition method for F/F/S heterostructures preparation, SQUID and low temperature resistance measurements for magnetic and transport characterization. In order to reach the objectives of the project the following steps will be taken: (a) The high quality F/F/S structures will be prepared using UHV method. In particular these systems will have the following set of layers IrMn/F1/Cu/F2/Pb (where F1 and F2 = Fe, Ni0.8Fe0.2 or Co2Cr1-xFexAl). Note that Co2Cr1-xFexAl is a Heusler alloy. It is a challenging experimental task itself to couple this material with a conventional superconducting S layer namely Pb. For this scheme in case of need the interface F2/Pb will be stabilized by nonmagnetic metal such as Cu in order to prevent mutual mixing between F2 and Pb materials. (b) The interplay between magnetic and superconducting properties will be investigated. Our preliminary work gives ground to suppose that as a fundamental research result of this challenging project:(1) the evidence of the triplet superconducting components in F/F/S scheme will be registered and their properties will be investigated and analyzed; (2) the full on/off switching of the superconductivity due to the superconducting triplet spin valve effect can be experimentally achieved.