Theory of resistivity upturns in metallic cuprates

Abstract

We propose that the experimentally observed resistivity upturn of cuprates at low temperatures may be explained by properly accounting for the effects of disorder in a strongly correlated metallic host. Within a calculation of the dc conductivity using real-space diagonalization of a Hubbard model treated in an inhomogeneous unrestricted Hartree-Fock approximation, we find that correlations induce magnetic droplets around impurities, and give rise to additional magnetic scattering which causes the resistivity upturn. A pseudogap in the density of states is shown to enhance both the disorder-induced magnetic state and the resistivity upturns.

Electrostatic Control of the Evolution from a Superconducting Phase to an Insulating Phase in UltrathinYBa2Cu3O7−xFilms

“…The low temperature upturn behavior is similar to that observed in amorphous MoGe films and granular superconductors [4,[33][34][35][36] and will dramatically affect any quantitative scaling analysis. We suggest that this is evidence of a mixed phase separating the superconducting and insulating regimes.…”

Transport anomalies and quantum criticality in electron-doped cuprate superconductors

“…Finkelman et al [38] found the spin-related MR was linear in field, inconsistent with the Kondo scattering which gives a log B dependence. They favors the picture of antiferromagnetic magnetic droplets [39]. Recently, Naito group [72] got superconductivity in parent compounds, and the upturn could be suppressed after a two-step 'protect annealing'.…”

“…The origin of crossover from metallic-to insulating-behavior, (i.e. upturn of resistivity) is still in debate, which may be subject to two-dimensional (2D) weak localization [35,36], Kondo-like scattering [37], additional scattering by magnetic droplets trapped at impurity sites [38,39], or a link to antiferromagnetism [40].…”

Persistent currents and spin torque caused by percolated quantum spin Hall state

“…The components b = {x, y, z} of the spin polarization induced by a longitudinal electric field E(i, t)x σ b (i, t) = χ b (i, ω)E(i, t) . (10) in our lattice model can be formulated within a linear response theory, where the real part of the DC magnetoelectric susceptibility is calculated by 25,26…”