This paper reports the measurements of resistivities near the superconductor-insulator transition for high-${\mathit{T}}_{\mathit{c}}$ oxide superconductor ${\mathrm{Nd}}_{2\mathrm{-}\mathit{x}}$${\mathrm{Ce}}_{\mathit{x}}$${\mathrm{CuO}}_4$ single-crystal thin films. The transition was tuned by magnetic fields and/or introducing disorder. The results of the resistivities are analyzed in line with dynamical scaling theory. The product of the dynamical exponent (${\mathit{z}}_{\mathit{B}}$) and the exponent for the correlation length (${\nu }_{\mathit{B}}$) is extracted. This value is consistent with that expected by the scaling theory. Our results provide the first evidence of the Bose-glass–vortex-glass phase transition in high-${\mathit{T}}_{\mathit{c}}$ ${\mathrm{Nd}}_{2\mathrm{-}\mathit{x}}$${\mathrm{Ce}}_{\mathit{x}}$${\mathrm{CuO}}_4$ single-crystal thin films.

• Received 21 April 1992

DOI:https://doi.org/10.1103/PhysRevLett.69.530