A step forward was taken on the road towards understanding novel effects for the development of innovative quantum technologies, thanks to a fruitful collaboration between the Istituto nanoscienze (Cnr Nano) of Pisa, the Department of Physics of the University of Salerno and Cnr SPIN Institute (based at the Physics Dept. of Salerno). The research was published in Physical Review Letters and was selected as “Editor’s Suggestion” due to its relevance.
The search for novel electronic devices to achieve greater energy efficiency, miniaturization, and speed of operation, aims at exploiting the quantum degrees of freedom of electrons, such as the angular momentum of spin and orbital, rather than their charge. In solids, the electronic states are formed by atomic orbitals and the corresponding orbital information, in analogy to the spin degree of freedom, can be controlled, manipulated and transported, giving life to a completely new type of electronics, called orbitronics. The research team, composed by Luca Chirolli and Francesco Giazotto of Cnr Nano, Maria Teresa Mercaldo and Claudio Guarcello of the Physics Department of Salerno, Mario Cuoco, of the Cnr SPIN – Salerno, recently discovered an effect conversion of supercurrent into a current that carries the orbital information of the electrons without dissipation.
The proposed Rashba-Edelstein orbital effect acquires a colossal character given the magnitude it manifests, when compared to the case of the conversion of supercurrent into a spin current. “Remarkably, we find that the supercurrent-induced orbital magnetization is more than 1 order of magnitude greater than that due to the spin”, says Luca Chirolli from Cnr Nano and first author of the study. The result opens the way to novel superconducting devices completely based on orbitronic and magneto-electric mechanisms and promotes materials with relevant orbital content as a novel platform for technological applications.
Colossal Orbital Edelstein Effect in Noncentrosymmetric Superconductors, Luca Chirolli, Maria Teresa Mercaldo, Claudio Guarcello, Francesco Giazotto, and Mario Cuoco, Phys. Rev. Lett. 128, 217703. DOI: 10.1103/PhysRevLett.128.217703
[Image credits: Phys. Rev. Lett.]