IRREVERSIBILITY BOUNDARIES OF BI2SR2CACU2O8, LA1.86SR0.14CUO4, AND YBA2CU3O7 - AN INTERPRETATION BASED ON THE VORTEX-LATTICE QUANTUM-MELTING MODEL

We have measured the irreversibility boundaries B(m)(T) of monocrystal line Bi2Sr2CaCu2O8, La1.86Sr0.14CuO4, and YBa2Cu3O7 near and below the respective critical temperatures T(c) for H//c. Near T(c), B(m)(T) ca n be approximated by a power law B(m)(T) = B0 (T(c)/T-1)n, with n appr oximately-equal-to 3/2 for LSCO and YBCO, but n almost-equal-to 2 for BSCCO. These results are in good agreement with the recently developed quantum-melting model for describing the irreversibility boundary, wh ich predicts significant quantum-fluctuation corrections to the positi onal fluctuations of the vortices in LSCO and YBCO, in distinct contra st to negligibly small corrections expected in BSCCO.