Abstracto

Properties of Spin Bath of Graphene?Like Nanocarbon

Arvind Kumar , Prashant S. Alegaonkar

Understanding and controlling the complex environment of solid–state quantum–bits is a central challenge in quantum information science and spintronics. We report on behavior of electron spin bath embedded in graphene–like nanocarbon (GNCs) superlattice. The GNCs were few layered, mixed sp2–sp3 phase, and contained local heavy vacancy disorder. The electron spectroscopy for chemical analysis indicated that, ratio of sp2:sp3 was 2:3 with native oxygen of ~ 6.75 atomic% attached to the sp3 sites. The spin transport data was obtained using electron spin resonance spectroscopy, carried out at 123–473K. Transport parameters were derived by deconvoluting Dysonian linewidth, and estimating anisotropy in Lande’s g–factor. The parameters such as spin–spin, spin–lattice relaxation time, and spin–orbit coupling constant were estimated and analyzed for their temperature and interdependence. The analysis revealed that, feeble magnetization exist due to charge inhomogeneities in GNCs yielding weak delocalization of –electrons. However, this delocalization is sufficiently useful to provide desired spin degrees of freedom to the spin bath. Analysis showed that, the bath have, practically, no effect of 2p–oxygen orbital quenching, the O–impurity existed in GNCs. These results open the door to understand coherent spin transport in GNCs. Designing spin bath with tuneable spin degrees of freedom is essential for solid state quantum–bits; vital organ of future quantum computational device. Details are presented.