Topological effects of the superconducting vortex state in a TaSe3 ring crystal : Observation of magnetic torque oscillations

概要

論文の詳細を見る
We measured the magnetic torque of the ring-shaped crystals of TaSe3 by using piezoresistive cantilevers to investigate the superconducting topological properties. We measured three ring samples and we observed that the magnetic torque of the ring crystals oscillates with increasing external magnetic field. The magnetic periods of Sample A (radius: 37.9 μm), Sample B (24.5 μm), and Sample C (15.6 μm) were 2.16 ± 6.6 x 10^[-2] G, 4.69 ± 1.8 x 10^[-1] G, and 5.44 ± 3.8 x 10^[-1] G, respectively. We found that hundreds of vortices collectively and simultaneously penetrated the ring crystal. When such a phenomenon occurs, it is natural that the vortices in the ring crystal would be positioned along the circumference. From these results, we suggest that vortices exist as cylinder vortices in the rings, and this phenomenon provides unambiguous experimental evidence of the topological effect in a superconductor.
2010-05-01