Metal-to-Insulator Crossover in the Low-Temperature Normal State of   Bi_{2}Sr_{2-x}La_{x}CuO_{6+\delta}
  We measure the normal-state in-plane resistivity of La-doped Bi-2201 single crystals at low temperatures by suppressing superconductivity with 60-T pulsed magnetic fields. With decreasing hole doping, we observe a crossover from a metallic to insulating behavior in the low-temperature normal state. This crossover is estimated to occur near 1/8 doping, well inside the underdoped regime, and not at optimum doping as reported for other cuprates. The insulating regime is marked by a logarithmic temperature dependence of the resistivity over two decades of temperature, suggesting that a peculiar charge localization is common to the cuprates. 
S. Ono, Yoichi Ando, T. Murayama (CRIEPI), F. F. Balakirev, J. B.   Betts, and G. S. Boebinger (NHMFL-LANL)