Metal-to-Insulator Crossover in the Low-Temperature Normal State of Bi_{2}Sr_{2-x}La_{x}CuO_{6+\delta}

摘要

We measure the normal-state in-plane resistivity of La-doped Bi-2201 singlecrystals at low temperatures by suppressing superconductivity with 60-T pulsedmagnetic fields. With decreasing hole doping, we observe a crossover from ametallic to insulating behavior in the low-temperature normal state. Thiscrossover is estimated to occur near 1/8 doping, well inside the underdopedregime, and not at optimum doping as reported for other cuprates. Theinsulating regime is marked by a logarithmic temperature dependence of theresistivity over two decades of temperature, suggesting that a peculiar chargelocalization is common to the cuprates.