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arXiv · 0810.5216

Calculated Magnetic Exchange Interactions in High-Temeprature Superconductors

Xiangang Wan·Thomas A. Maier·Sergej Y. Savrasov
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Abstract

Using a first principles linear response approach, we study the magnetic exchange interactions J for a series of superconducting cuprates. We reproduce the observed spin-wave dispersions together with other experimental trends, and show that different cuprates have similar J's regardless their T$_{c}$. The nearest neighbor J is not sensitive to the hole-doping, which agrees with recent experiments. For the undoped cuprates, the second nearest neighbor J is ferromagnetic, but changes its sign with hole-doping. We also find that, in contrast to the hopping integral, the exchange interaction is not sensitive to the position of apical oxygen. To see the effect of the long--range nature of the exchange on the superconducting T$_{c}$, we study the dynamical spin susceptibility $χ(q,ω)$ within the t--J model using a dynamical cluster approximation.

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Xiangang Wan, Thomas A. Maier, Sergej Y. Savrasov. 2009-03-24. Calculated Magnetic Exchange Interactions in High-Temeprature Superconductors. https://doi.org/10.1103/physrevb.79.155114

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