Observation of individual vortices trapped along columnar defects in high-temperature superconductors

Tonomura, A.*; Hasai, H.*; Kamimura, O.*; Matsuda, T.*; Harada, K.*; Nakayama, Y.*; Shimoyama, J.*; Kishio, K.*; Hanaguri, T.*; Kitazawa, K.*; et al.

Nature, 412(6847), p.620 - 622, 2001/08

https://doi.org/10.1038/35088021

Direct observation microscopically elucidated the behaviour of vortices in Bi-2212 thin films. The isotropic pinning of vortices by columnar defects at low magnetic fields indirectly inferred by macroscopic magnetization measurements can be explained microscopically as follows; vortex lines are trapped along columns ate temperatures above 19K irrespective of the direction of the applied magnetic field; and at temperatures below 12K vortex lines always penetrate the film perpendicularly to the film plane owing to the increased background pinning compared to the columnar-defect pinning and also because of the demagnetization effect of thin film.