Search for magnetic fields due to anyons in high-Tc superconductors

We have searched for anomalous internal magnetic fields in highTc materials which are predicted to occur in anyon and flux phase models of superconductivity. The magnitude, anisotropy and temperature dependence of the observed fields inc-axis oriented samples of sintered YBa2CuO3O7 and of thick-film Bi2Sr2CaCu2O8 are consistent with a conventional nuclear dipolar origin. An upper limit of ≲0.08 mT is set for any anomalous magnetic fields along thec-axis atμ+ sites in bulk CuO2 superconductors.