Anisotropy of the coherence length from critical currents in the stoichiometric superconductor LiFeAs

Marcin Konczykowski (1) , Cornelis Jacominus van Der Beek (1) , Makariy A. Tanatar (2) , Vincent Mosser (3) , Yoo Jang Song (4) , Yong Seung Kwon (4) , Ruslan Prozorov (2, 5)

1 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory
2 Ames Laboratory [Ames, USA]
3 ITRON - itron
4 SKKU - Sungkyunkwan University [Suwon]
5 Department of Physics and Astronomy [Ames, Iowa]

of vortex motion in the stoichiometric LiFeAs superconductor. These correspond to vortex lines along the c axis moving parallel to the ab plane, and to vortex lines in the ab plane moving perpendicular to and within the plane, respectively. The measurements were carried out in the low-field regime of strong vortex pinning, in which the critical current anisotropy is solely determined by the coherence length anisotropy parameter εξ . This allows for the extraction of εξ at magnetic fields far below the upper critical field Bc2. We find that increasing the magnetic field decreases the anisotropy of the coherence length.

Mots clés: Supraconductivité; Superconductivity; Iron-pnictides; Pnictures de fer; Superconducting vortices; Vortex supraconducteurs; Ancrage de vortex; vortex pinning; Critical current; Courant critique; Anisotropy; Mutli-band superconductors; Supraconductivité à multiples bandes; Magnétométrie à sondes à effet Hall; Hall probe magnetometry

Domaines: Supraconductivité [cond-mat.supr-con]

Marcin Konczykowski, Cornelis Jacominus van Der Beek, Makariy A. Tanatar, Vincent Mosser, Yoo Jang Song, et al.. Anisotropy of the coherence length from critical currents in the stoichiometric superconductor LiFeAs. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2011, 84, pp.180514(R). ⟨10.1103/PhysRevB.84.180514⟩. ⟨hal-00659727⟩