Comparison of the transport mechanism in underdoped high-temperature superconductors and in spin ladders

Abstract

Recently, the normal state resistivity of high temperature superconductors (in particular in La2-xSrxCuO4 single crystals) has been studied extensively in the region below Tc by suppressing the superconducting state in high magnetic fields [1] . In the present work we report on the normal state resistance of underdoped La2-xSrxCuO4 thin films under epitaxial strain [2] , measured far below Tc by applying pulsed fields up to 60 T [3] . We will compare the transport measurements on these high temperature superconductors with transport data reported for the Sr2.5Ca11.5Cu24O41 spin ladder compound [4] . This comparison leads to an interpretation of the data in terms of the recently proposed 1D quantum transport model and the charge-stripe models [5,6]

Collective Density-Wave Excitations in Two-LegSr14−xCaxCGozar1, Blumberg2, Littlewood3 et al. 2003Phys. Rev. Lett.223292View full textAdd to dashboardCite

“…The ladder carrier density was estimated from the optical spectral weight to increase from 0.07 for x 0 to about 0.2 for x 11 Sr 14ÿx Ca x Cu 24 O 41 [6]. While Sr 14 Cu 24 O 41 is an insulator, a crossover to metallic conduction at high temperatures takes place around x 11 and for x 12 the c-axis dc resistivity has a minimum around T 70 K separating quasilinear metallic and insulating behavior very similar to the case of high-T c cuprates in the underdoped regime [7][8][9][10] In the case of a DW instability, theory predicts the existence of phase and amplitude collective modes of the DW order parameter [12]. In an ideal system the current carrying phase mode can slide without friction [13], while impurities or lattice commensurability destroy the infinite conductivity and shift this mode to finite frequency as has been experimentally observed [14,15].…”

Normal state resistivity of underdoped YBa2Cu3O7-d films and La2-XSrXCuO4 ultra-thin films in fields up to 60 T

“…Moreover, in the right plot it is shown that, not only does the ρ(T) expression for the 1D stripes fit good, also a scaling between the Sr 2.5 Ca 11.5 Cu 24 O 41 spin-ladder compound under pressure [6] and the underdoped La 1.9 Sr 0.1 CuO 4 is proven for T/T o < 0.6. Since, in the spin ladder compound, it is known that the transport mechanisms are dominated by the 1D magnetic scattering, this further motivates the principles of our approach [4,5]. Fitting the 1D region (II) with the proper expression reveals a gap ∆ ≈ 216 K.…”

“…(right plot) Critical temperature T c and spin gap ∆ versus the oxygen content x of YBa 2 Cu 3 O x . The proper ρ(T) expressions [4,5] for the 3 regions are given; ∆ is the spin gap and J indicates the interaction energy.…”

“…More features of the model used to describe the measurements [4,5] are summarised in figure 1. The model is based on the following basic principles: The Cu-O HTS, all have CuO 2 planes as building blocks.…”