Electronic States of doped spin ladders (Sr,Ca)14Cu24O41

Abstract

We examine the electronic states of Sr${}_{14-x}$Ca${}_x$Cu${}_{24}$O${}_{41}$ by the ionic and cluster model approach. It is found that self-doped holes are likely to stay on the chain at $x=0$ and the Ca substitution drives the holes to move to the ladder. This feature is caused by the change of the positions of (Sr,Ca) layers, which enhances the electrostatic potentials in the chain. The optical conductivity is calculated applying the exact diagonalization method to small Cu-O clusters. It is shown that the excitations below 2 eV are governed by the ladder, giving rise to the spectral weight transfer from the charge-transfer excitation around 2 eV to low energy Drude excitation, while the contribution from the chain mainly emerges in higher energy region showing large weight around 3 eV. These provide consistent explanation to recent experiment.

8 pages, LaTeX, 4 postscript figures

Cited by in corpus (25)

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• Hole distribution for (Sr,Ca,Y,La)_14 Cu_24 O_41 ladder compounds studied by x-ray absorption spectroscopy
• Observation of two-magnon bound states in the two-leg ladders of (Ca,La)14Cu24O41
• Electronic structure and magnetic properties of the linear chain cuprates Sr_2CuO_3 and Ca_2CuO_3
• Spectral Properties of Magnetic Excitations in Cuprate Two-Leg Ladder Systems
• Quasi-two-dimensional hole ordering and dimerized state in the CuO2-chain layers in Sr14Cu24O41
• Electronic Structures of Sr_{14-x}Ca_{x}Cu24O41
• Electronic Structure of Ladder Cuprates
• Optical Properties of the Spin-Ladder Compound Sr_{14}Cu_{24}O_{41}
• Hole redistribution in Sr\_(14-x)Ca\_xCu\_24O\_41 (x = 0, 12) spin ladder compounds: ^63Cu and ^17O NMR study under pressure
• Influence of the incommensurability in $S{r}_{14-x}C{a}_{x}C{u}_{24}{O}_{41}$ family compounds
• Raman Response of Magnetic Excitations in Cuprate Ladders and Planes
• Momentum Dependent Charge Excitations of Two-Leg Ladder: Resonant Inelastic X-ray Scattering of (La,Sr,Ca)14Cu24O41
• Phase Diagram of Coupled Ladders
• Dimensional Crossovers in the Doped Ladder System: Spin Gap, Superconductivity and Interladder Coherent Band Motion
• Charge order induced sharp Raman peak in Sr_14Cu_24O_41
• Crossover of the high-energy spin fluctuations from collective triplons to localized magnetic excitations in doped Sr14-xCaxCu24O41 cuprate ladders
• Influence of doping on the Hall coefficient in Sr_{14-x}Ca_xCu_24O_41
• Enhanced magnetocaloric effect in a mixed spin-(1/2, 1) Ising-Heisenberg two-leg ladder with strong-rung interaction
• Two-Dimensionality of Magnetic Excitations on the Trellis Lattice: (La,Sr,Ca)${}_{14}$Cu${}_{24}$O${}_{41}$ and SrCu${}_2$O${}_3$
• Pressure-induced phase transition and bi-polaronic sliding in a hole-doped Cu_2O_3 ladder system
• Valence Transition Theory of the Pressure-Induced Dimensionality Crossover in Superconducting Sr${}_{14-x}$Ca${}_x$Cu${}_{24}$O${}_{41}$
• Electronic States and Excitation Spectra of Copper Oxides with Ladder and/or Chain
• Charge order in the incommensurate compounds $Sr\_14-xCa\_xCu\_24O\_41$