Vortex matter freezing in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ samples with   a very dense distribution of columnar defects
  We show that the dynamical freezing of vortex structures nucleated at diluted densities in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ samples with a dense distribution of columnar defects, $B \sim 10^{-2} B_{\Phi}$ with $B_{\Phi}=5$\,kG, results in configurations with liquid-like correlations. We propose a freezing model considering a relaxation dynamics dominated by double-kink excitations driven by the local stresses obtained directly from experimental images. With this model we estimate the relaxation barrier and the freezing temperature. We argue that the low-field frozen vortex structures nucleated in a dense distribution of columnar defects thus correspond to an out-of-equilibrium non-entangled liquid with strongly reduced mobility rather than to a snapshot of a metastable state with divergent activation barriers as for instance expected for the Bose-glass phase at equilibrium. 
N. R. Cejas Bolecek and A. B. Kolton and M. Konczykowski and H.   Pastoriza and D. Dom\'inguez and Y. Fasano
cond-mat.supr-con