Spin-Waves in the Mid-Infrared Spectrum of Antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$

M. Grüninger; J. Münzel; A. Gaymann; A. Zibold; H. P. Geserich; T. Kopp

doi:10.1209/epl/i1996-00530-3

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Spin-Waves in the Mid-Infrared Spectrum of Antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$

M. Grüninger·J. Münzel·A. Gaymann·A. Zibold·H. P. Geserich·T. Kopp

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Abstract

The mid-infrared spin-wave spectrum of antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$\ was determined by infrared transmission and reflection measurements ($\bbox{k} \!\! \parallel $c) at $T\!=\!10\!$~K.\@ Excitation of single magnons of the optical branch was observed at $E_{\text{op}}\!=\!178.0\!$~meV.\@ Two further peaks at $346\!$~meV ($\approx\!1.94\,E_{\text{op}}$) and $470\!$~meV ($\approx\!2.6\,E_{\text{op}}$) both belong to the two-magnon spectrum. Linear spin wave theory is in good agreement with the measured two-magnon spectrum, and allows to determine the exchange constant $J$ to be about $120\!$~meV, whereas the intrabilayer coupling $J_{12}$ is approximately $0.55\,J$.

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M. Grüninger, J. Münzel, A. Gaymann, A. Zibold, H. P. Geserich, T. Kopp. 1995-01-16. Spin-Waves in the Mid-Infrared Spectrum of Antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$. https://doi.org/10.1209/epl%2Fi1996-00530-3

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