Transport properties of vortex matter governed by the edge inductance in superconducting Bi2 Sr2 CaCu2 O8 crystals

We study the distribution of transport current across superconducting Bi2 Sr2 CaCu2 O8 crystals and the vortex flow through the sample edges. We show that the Tx transition is of electrodynamic rather than thermodynamic nature, below which vortex dynamics is governed by the edge inductance instead of the resistance. This allows measurement of the resistance down to 2 orders of magnitude below the transport noise. By irradiating the current contacts the resistive step at vortex melting is shown to be due to loss of c -axis correlations rather than breakdown of quasilong-range order within the a-b planes.