2001/11/08 by Atsutaka Maeda, A. Maeda, T. Tsuboi +10 · 1 citation
Physics and Astronomy · #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.65.054506
9 pages (text), 1 table, 12 figures
arxiv created 2001/11/08 · openalex publication_date 2002/01/03 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
To investigate the dynamics of driven vortices in superconductors, noise in the local vortex density was investigated in the mixed state of a high-Tc superconductor, Bi2Sr2CaCu2Oy, using a two-dimensional electron gas micro-Hall probe array. We studied the cross-correlation function, together with the autocorrelation function, both parallel and perpendicular to the direction of flow of the vortices. The broadband noise (BBN) did not have large spatial correlations. This suggests that the BBN is due to the fluctuation of the local vortex density generated by bulk pinning centers under the area of each probe. On the other hand, the narrow-band noise (NBN) (with the time scale of the transit time of vortices) had large translational correlations. These definitely show that the NBN was generated by semimacroscopic imperfections like the surface, macroscopic line defects, etc. In relation to the dynamic phase diagram, large BBN was observed when the vortices started moving. The dependence of the spatial correlations on the direction of the array relative to the direction of the driving current suggested that plastic flow was present when the large BBN was observed. The gross features of our data agree well with some of the theoretically proposed dynamical phase diagrams of vortices in superconductors.