2005/05/13 by M. C. Sullivan, Douglas R. Strachan, D. R. Strachan +5
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.72.092507
published as Phys. Rev. B 72, 092507 (2005) · 4 pages, 4 figures
arxiv created 2005/05/13 · openalex publication_date 2005/09/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Researchers have studied the normal-superconducting phase transition in the high-Tc cuprates in a magnetic field (the vortex-glass or Bose-glass transition) and in zero field. Often, transport measurements in ``zero field'' are taken in the Earth's ambient field or in the remnant field of a magnet. We show that fields as small as the Earth's field will alter the shape of the current vs voltage curves and will result in inaccurate values for the critical temperature Tc and the critical exponents \ensuremathν and z, and can even destroy the phase transition. This indicates that without proper screening of the magnetic field it is impossible to determine the true zero-field critical parameters, making correct scaling and other data analysis impossible. We also show, theoretically and experimentally, that the self field generated by the current flowing in the sample has no effect on the current vs voltage isotherms.