Little-Parks oscillations with half-quantum fluxoid features in Sr2RuO4 micro rings

Autor: Yasui, Yuuki, Lahabi, Kaveh, Anwar, Muhammad Shahbaz, Nakamura, Yuji, Yonezawa, Shingo, Terashima, Takahito, Aarts, Jan, Maeno, Yoshiteru
Rok vydání: 2017
Předmět:
Zdroj: Phys. Rev. B 96 (2017) 180507(R)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.96.180507
Popis: In a micro ring of a superconductor with a spin-triplet equal-spin pairing state, a fluxoid, a combined object of magnetic flux and circulating supercurrent, can penetrate as half-integer multiples of the flux quantum. A candidate material to investigate such half-quantum fluxoids is Sr$_\mathsf{2}$RuO$_\mathsf{4}$. We fabricated Sr$_\mathsf{2}$RuO$_\mathsf{4}$ micro rings using single crystals and measured their resistance behavior under magnetic fields controlled with a three-axes vector magnet. Proper Little-Parks oscillations in the magnetovoltage as a function of an axially applied field, associated with fluxoid quantization are clearly observed, for the first time using bulk single crystalline superconductors. We then performed magnetovoltage measurements with additional in-plane magnetic fields. By carefully analyzing both the voltages $V_+$ ($V_-$) measured at positive (negative) current, we find that, above an in-plane threshold field of about 10 mT, the magnetovoltage maxima convert to minima. We interpret this behavior as the peak splitting expected for the half-quantum fluxoid states.
Comment: 16 pages, 15 figures
Databáze: arXiv