Ultralong Spin Lifetime in Light Alkali Atom Doped Graphene
Bence G. Márkus, Péter Szirmai, Konstantin F. Edelthalhammer, P. Eckerlein, Andreas Hirsch, Frank Hauke, N. M. Nemes, Julio C. Chacón‐Torres, Bálint Náfrádi, L. Forró, Thomas Pichler, Ferenc Simon
Abstract
Today's great challenges of energy and informational technologies are addressed with a singular compound, Li- and Na-doped few-layer graphene. All that is impossible for graphite (homogeneous and high-level Na doping) and unstable for single-layer graphene works very well for this structure. The transformation of the Raman G line to a Fano line shape and the emergence of strong, metallic-like electron spin resonance (ESR) modes attest the high level of graphene doping in liquid ammonia for both kinds of alkali atoms. The spin-relaxation time in our materials, deduced from the ESR line width, is 6-8 ns, which is comparable to the longest values found in spin-transport experiments on ultrahigh-mobility graphene flakes. This could qualify our material as a promising candidate in spintronics devices. On the other hand, the successful sodium doping, this being a highly abundant metal, could be an encouraging alternative to lithium batteries.