We theoretically propose a principle for precise measurement of oscillatory domain wall (DW) by a ferromagnetic Josephson junction, which is composed of a ferromagnetic wire with DW and two superconducting electrodes. The current-voltage curve exhibits stepwise structures, only when DW oscillates in the ferromagnetic wire. The voltage step appears at V = n(\hbar/2e)\omega_DW with the fundamental constant \hbar/e, integer number n, and the DW frequency \omega_DW. Since V can be determined in the order of 10^9 accuracy, the oscillatory DW will be measured more precisely than present status by conventional method.
@article{arxiv.1202.0382,
title = {Towards precise measurement of oscillatory domain wall by ferromagnetic Josephson junction},
author = {Shin-ichi Hikino and Michiyasu Mori and Wataru Koshibae and Sadamichi Maekawa},
journal= {arXiv preprint arXiv:1202.0382},
year = {2012}
}