Possible method to observe the breathing mode of a magnetic domain wall in the Josephson junction

Mori, Michiyasu  ; Koshibae, Wataru*; Hikino, Shinichi*; Maekawa, Sadamichi

A magnetic domain wall (DW) behaves as a massive particle with elasticity. Sliding and oscillation of the DW have been observed experimentally, whereas vibration of a width in the DW, "breathing mode", has not been measured so far. We theoretically propose how to observe the breathing mode by the Josephson junction having a ferromagnetic layer between superconducting electrodes. The current-voltage (-) curve is calculated by an equivalent circuit of the resistively shunted junction model. The breathing mode is identified by stepwise structures in the - curve, which appear at the voltages =) with the fundamental constant , integer number , and the frequency of the breathing mode .