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arXiv · 1409.4818

Phonon-modulated magnetic interactions and spin Tomonaga-Luttinger liquid in the p-orbital antiferromagnet CsO2

M. Klanjsek·D. Arcon·A. Sans·P. Adler·M. Jansen·C. Felser
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Abstract

The magnetic response of antiferromagnetic CsO2, coming from the p-orbital S=1/2 spins of anionic O2- molecules, is followed by 133Cs nuclear magnetic resonance across the structural phase transition occuring at Ts1=61 K on cooling. Above Ts1, where spins form a square magnetic lattice, we observe a huge, nonmonotonic temperature dependence of the exchange coupling originating from thermal librations of O2- molecules. Below Ts1, where antiferromagnetic spin chains are formed as a result of p-orbital ordering, we observe a spin Tomonaga-Luttinger-liquid behavior of spin dynamics. These two interesting phenomena, which provide rare simple manifestations of the coupling between spin, lattice and orbital degrees of freedom, establish CsO2 as a model system for molecular solids.

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M. Klanjsek, D. Arcon, A. Sans, P. Adler, M. Jansen, C. Felser. 2014-09-16. Phonon-modulated magnetic interactions and spin Tomonaga-Luttinger liquid in the p-orbital antiferromagnet CsO2. https://doi.org/10.1103/physrevlett.115.057205

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