Geometric edge barrier in the Shubnikov phase of type II superconductors

• Published in: Физика низких температур
• Date: 2001
• Main Author: Brandt, E.H.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2001
• Subjects: Статьи, посвященные столетию со дня рождения Л. В. Шубникова
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/129001
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Geometric edge barrier in the Shubnikov phase of type II superconductors / E.H. 
 
 Brandt // Физика низких температур. — 2001. — Т. 27, № 9-10. — С. 980-990. — Бібліогр.: 51 назв. — англ.

In type II superconductors the magnetic response 
 
 can be irreversible due to two different reasons: vortex pinning and barriers for flux 
 
 penetration. Even without bulk pinning and in absence of a microscopic Bean-Livingston 
 
 surface barrier for vortex penetration, superconductors of nonellipsoidal shape can exhibit 
 
 a large geometric barrier for flux penetration. This edge barrier and the resulting 
 
 irreversible magnetization loops and flux-density profiles are computed from continuum 
 
 electrodynamics for superconductor strips and disks with constant thickness, both without 
 
 and with bulk pinning. Expressions are given for the field of first flux entry Hen and for 
 
 the reversibility field Hrev above which the pin-free magnetization becomes reversible. 
 
 Both fields are proportional to the lower critical field Hc1 but else depend only on the 
 
 specimen shape. These results for rectangular cross section are compared with the well 
 
 known reversible magnetic behavior of ideal ellipsoids.