Weak magnetic order in high-Tc superconductors produced by spontaneous Josephson currents
1 Department of Physics, Simon Fraser University - Burnaby, British Columbia, Canada V5A 1S6
2 Instituto de Física, Universidade Federal Fluminense - Niterói, RJ 24210-340, Brazil
Received: 2 January 2013
Accepted: 13 March 2013
We develop a model for high-Tc superconductors based on an electronic phase separation where low-and high-density domains are formed. At low temperatures this system may act as a granular superconductor forming an array of Josephson junctions. Cuprates are also known to have low superfluid densities and strong correlation effects. Both characteristics activate a negative Josephson coupling due to frustration that leads to spontaneous currents responsible for the weak ferromagnetic order. This original approach reproduces the observed onset of spontaneous magnetic signal and its dependence on the doping level.
PACS: 74.20.Mn – Nonconventional mechanisms / 74.81.Fa – Josephson junction arrays and wire networks / 74.62.En – Effects of disorder
© EPLA, 2013