Comment on "Field-enhanced diamagnetism in the pseudogap state of the cuprate Bi(2)Sr(2)CaCu(2)O(8+delta) superconductor in an intense magnetic field".

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 ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}$, we uncover a field-enhanced diamagnetic signal $M$ above the transition temperature ${T}_{c}$ that increases with applied field to 32 Tesla and scales just like the Nernst signal. The magnetization results above ${T}_{c}$ distinguish $M$ from conventional amplitude fluctuations and strongly support the vortex scenario for the loss of phase coherence at ${T}_{c}$.