Incommensurate magnetism in cuprate materials

Abstract

In the low doping region an incommensurate magnetic phase is observed in LSCO. By means of the composite operator method we show that the single-band 2D Hubbard model describes the experimental situation. In the higher doping region, where experiments are not available, the incommensurability is depressed owing to the van Hove singularity near the Fermi level. A proportionality between the incommensurability amplitude and the critical temperature is predicted, suggesting a close relation between superconductivity and incommensurate magnetism.Comment: 4 pages, 5 figures in one Postscript file, RevTe

Stripe order, depinning, and fluctuations inLa1.875Ba0.125CuO4andFujita1, Goka2, Yamada3 et al. 2004Phys. Rev. B326453581View full textAdd to dashboardCite

“…To us, the concept of fluctuating stripes 15,16 provides an appealing explanation of the magnetic fluctuations; however, there is an alternative school of thought that argues for an explanation in terms of Fermi-surface-nesting effects. 17,18,19,20,21,22,23 This controversy is tied to the issue of whether chargestripe order is incompatible with superconductivity. It is clear experimentally that static ordering of charge stripes is correlated with a depression of T c , 24,25 but are the excitations of the stripe-ordered state different in nature from those in a state without static stripe order?…”

New Comparisons for Local Quantities of the Two-Dimensional Hubbard Model

“…The straightforward application of this scheme 8 ' [10][11][12][13] gives that, in the paramagnetic phase, J(k) has diagonal form with In = 1 -n/2 and I22 -n/2 ((n a (i)) -j) and that the m-matrix depends on three parameters: the chemical potential /x and two correlators…”

The two-dimensional t-t'-U model as a minimal model for cuprate materials

“…In the last years we have been developing a method of calculation, denominated Composite Operator Method [19][20][21][22][23][24][25] (COM), which has been revealed to be a powerful tool for the description of local and itinerant excitations in strongly correlated electronic systems. The method is based on the observation that the original field operators, in terms of which the interacting Hamiltonians are expressed, are not a convenient basis.…”