Abstract
In hole-doped cuprates, Nernst experiments imply that the superconducting state is destroyed by spontaneous creation of vortices which destroy phase coherence. Using torque magnetometry on , we uncover a field-enhanced diamagnetic signal above the transition temperature that increases with applied field to 32 Tesla and scales just like the Nernst signal. The magnetization results above distinguish from conventional amplitude fluctuations and strongly support the vortex scenario for the loss of phase coherence at .
- Received 21 March 2005
DOI:https://doi.org/10.1103/PhysRevLett.95.247002
©2005 American Physical Society