Type-1.5 superconductivity.
We demonstrate the existence of a novel superconducting state in high quality two-component MgB2 single crystalline superconductors where a unique combination of both type-1 (lambda{1}/xi{1}<1/sqrt[2]) and type-2 (lambda{2}/xi{2}>1/sqrt[2]) superconductor conditions is realized for the two components of the order parameter. This condition leads to a vortex-vortex interaction attractive at long distances and repulsive at short distances, which stabilizes unconventional stripe- and gossamerlike vortex patterns that we have visualized in this type-1.5 superconductor using Bitter decoration and also reproduced in numerical simulations.
Moshchalkov
Victor
V
INPAC-Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium. victor.moshchalkov@fys.kuleuven.be
Menghini
Mariela
M
Nishio
T
T
Chen
Q H
QH
Silhanek
A V
AV
Dao
V H
VH
Chibotaru
L F
LF
Zhigadlo
N D
ND
Karpinski
J
J