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arXiv · 0810.3068

Pnictides as frustrated quantum antiferromagnet close to a quantum phase transition

Goetz S. Uhrig·Michael Holt·Jaan Oitmaa·Oleg P. Sushkov·Rajiv R. P. Singh
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Abstract

We present a detailed description of the dynamics of the magnetic modes in the recently discovered superconducting pnictides using reliable self-consistent spin-wave theory and series expansion. Contrary to linear spin-wave theory, no gapless mode occurs at the Néel wave vector. We discuss the scenario that the static magnetic moment is strongly reduced by magnetic fluctuations arising from the vicinity to a quantum phase transition. Smoking gun experiments to verify this scenario are proposed and possible results are predicted. Intriguingly in this scenario, the structural transition at finite temperature would be driven by an Ising transition in directional degrees of freedom.

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Goetz S. Uhrig, Michael Holt, Jaan Oitmaa, Oleg P. Sushkov, Rajiv R. P. Singh. 2009-02-09. Pnictides as frustrated quantum antiferromagnet close to a quantum phase transition. https://doi.org/10.1103/physrevb.79.092416

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