Local modification of magnetic properties of nanoelements is a key to design future-generation magnonic devices, in which information is carried and processed via spin waves. One of the biggest challenges here is to fabricate simple and miniature phase-controlling elements with broad tunability. Here, we successfully realize such spin-wave phase shifter upon a single nanogroove milled by focused ion beam in a Co-Fe microsized magnonic waveguide. By varying the groove depth and the in-plane bias magnetic field we continuously tune the spin-wave phase and experimentally evidence a complete phase inversion. The microscopic mechanism of the phase shift is based on the combined action of the nanogroove as a geometrical defect and the lower spin-wave group velocity in the waveguide under the groove where the magnetization is reduced due to the incorporation of Ga ions during the ion-beam milling. The proposed phase shifter can easily be on-chip integrated with spin-wave logic gates and other magnonic devices. Our findings are crucial for designing nano-magnonic circuits and for the development of spin-wave nano-optics.
@article{arxiv.1902.03758,
title = {Spin-wave phase inverter upon a single nanodefect},
author = {O. V. Dobrovolskiy and R. Sachser and S. A. Bunyaev and D. Navas and V. M. Bevz and M. Zelent and W. Smigaj and J. Rychly and M. Krawczyk and R. V. Vovk and M. Huth and G. N. Kakazei},
journal= {arXiv preprint arXiv:1902.03758},
year = {2020}
}