We make a comparative study between the $\mathrm{ab}$ plane’s dc critical current and the ac transverse magnetic permeability ${\mu }_{\perp }$ in the Campbell limit for optimally doped and overdoped ${\mathrm{Bi}}_2{\mathrm{Sr}}_2{\mathrm{CaCu}}_2{\mathrm{O}}_{8+\delta }$ samples. We focus attention on the low-temperature region $\left[{T/T}_c\mathrm{}\right(0)<0.25\mathrm{}],$ where the transition to the zero-dimensional Larkin limit is detected by the critical current as well as by a rapid change of the Labusch parameter with temperature. The order-disorder transition, characterized by the second peak in magnetization, disappears in the presence of this zero-dimensional pinning regime.

• Received 29 February 2000

DOI:https://doi.org/10.1103/PhysRevB.63.092502