Superconducting quantum spintronics

Abstract

Long-range and long lifetime spin current has much been desired for robustness of spintronics applications, particularly in quantum computing application. The interplay between ferromagnetism and superconductivity is limited by the strong exchange interaction, that destroys the superconducting state. However, it is possible that through spin-triplet Cooper pairing, long-range superconductivity in ferromagnet can occur. In this study, electrical transport property due to proximity effect between FGT a ferromagnet (FM) and NbSe2 a superconductor (SC) heterostructure, using Hall bar configuration was investigated under varying temperature, bias current, remanent magnetization of ferromagnetic layer and external magnetic field. The longitudinal and Hall measurement under superconducting and non-superconducting state were used to interpret charge carrier transportation in the heterostructure. Superconducting state was observed in the device below critical temperature, through longitudinal measurements. The sample reveals abnormal peak(s) in Hall measurements during superconductivity transition, between onset to complete transition, with and without the presence of applied magnetic field. The peak(s) suggests charge imbalance and possible spin imbalance, and could be also possibly attributed to the interaction between mixed state in type II SC and proximity effect of FM.