Superconducting effective-mass anisotropy in Tl2Ba2CaCu2Ox

Abstract
Using torque magnetometry, we have obtained a lower bound of ∼105 for the anisotropy of the superconducting effective mass in a single crystal of Tl2 Ba2 CaCu2 Ox. This is the largest such anisotropy yet reported for a high-Tc material.