Two mechanisms of pseudogap formation in Bi-2201: Evidence from the c-axis magnetoresistance
arXiv:cond-mat/0111004 · doi:10.1209/epl/i2002-00571-0
Abstract
Measurements of the c-axis resistivity and magnetoresistance have been used to investigate the pseudogap (PG) behavior in Bi_{2+z}Sr_{2-x-z}La_xCuO_y (Bi-2201) crystals at various hole densities. While the PG opening temperature T* increases with decreasing hole doping, the magnetic-field sensitivity of the PG is found to have a very different trend: it appears at lower temperatures in more underdoped samples and vanishes in non-superconducting samples. These data suggest that besides the field-insensitive pseudogap emerging at T*, a distinct one is formed above T_c as a precursor to superconductivity.
7 pages, 6 figures, accepted for publication in Europhysics Letters (initially submitted to PRL on 14 June 2000)