Laser-induced ultrafast spin dynamics and {ERASE} functionality on quasilinear molecular ions

We present an \emph{ab initio} investigation of the $\Lambda$-process-based ultrafast spin manipulation on positively charged two-magnetic-center molecular ions bridged by non-magnetic oxygen\footnote{C. Li, S. Zhang, G. Lefkidis, and W. H\"{u}bner, Phys. Rev. B {\bf 89}, 184404 (2014)}. Multiple derived spin-switching and spin-transfer scenarios on the quasilinear structure [Fe-O-Co]$^{+}$ are used to build two closed, irreversible spin-dynamics cycles with respect to the spin localization and orientation. A mechanism addressing the ``ERASE'' functionality is proposed by properly exploiting the irreversibility of some laser-induced spin-manipulation scenarios, and the resulting Shannon entropy change is analyzed. We compare with a presiously suggested mechanism based on chirped laser pulses\footnote{G. P. Zhang, G. Lefkidis, W. H\"{u}bner, and Y. Bai, J. Appl. Phys. {\bf 111}, 07C508 (2012)}. Such controllable spin-dynamics cycles and logic functionality demonstrate promising applications in the design of spintronic devices on isolated magnetic molecules\footnote{ W. Jin, F. Rupp, K. Chevalier, M. M. N. Wolf, M. Colindres Rojas, G. Lefkidis, H.-J. Kr\"{u}ger, R. Diller, and W. H\"{u}bner Phys. Rev Lett. {\bf 109}, 267209 (2012) }.