Magnetization, Nernst effect and vorticity in the cuprates

Nernst and magnetization experiments reveal the existence of a large region of the cuprate phase diagram above the T-c curve in which vorticity and weak diamagnetism exist without phase coherence. We discuss the implication that the transition at T-c is caused by the loss of long-range phase coherence caused by spontaneous vortex creation. Below T-c, these measurements provide an estimate of the depairing field H-c2 which is found to be very large (40-100 T depending on doping). We discuss the high-field Nernst and magnetization results, binding energy, and the phase diagram of hole-doped cuprates. Some new magnetization results on the vortex liquid in very underdoped LSCO in the limit T -> 0 are reported as well. (c) 2006 Elsevier B.V. All rights reserved.