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arXiv · 1901.02102

Spin dynamics of edge-sharing spin chains in SrCa13Cu24O41

Guochu Deng·Dehong Yu·Richard Mole·Ekaterina Pomjakushina·Kazimierz Conder·Michel Kenzelmann·Shin-ichiro Yano·Chin-Wei Wang·Kirrily C. Rule·Jason S. Gardner·Huiqian Luo·Shiliang Li·Clemens Ulrich·Paolo Imperia·Wei Ren·Shixun Cao·Garry J. McIntyrea
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Abstract

The low-energy magnetic excitation from the highly Ca-doped quasi-one-dimensional magnet SrCa13Cu24O41 was studied in the magnetic ordered state by using inelastic neutron scattering. We observed the gapless spin-wave excitation, dispersive along the a and c axes but nondispersive along the b axis. Such excitations are attributed to the spin wave from the spin-chain sublattice. Model fitting to the experimental data gives the nearest-neighbour interaction Jc as 5.4 meV and the interchain interaction Ja = 4.4 meV. Jc is antiferromagnetic and its value is close to the nearest-neighbour interactions of the similar edge-sharing spin-chain systems such as CuGeO3. Comparing with the hole-doped spin chains in Sr14Cu24O41, which shows a spin gap due to spin dimers formed around Zhang-Rice singlets, the chains in SrCa13Cu24O41 show a gapless excitation in this study. We ascribe such a change from gapped to gapless excitations to holes transferring away from the chain sublattice into the ladder sublattice upon Ca doping.

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Guochu Deng, Dehong Yu, Richard Mole, Ekaterina Pomjakushina, Kazimierz Conder, Michel Kenzelmann, Shin-ichiro Yano, Chin-Wei Wang, Kirrily C. Rule, Jason S. Gardner, Huiqian Luo, Shiliang Li, Clemens Ulrich, Paolo Imperia, Wei Ren, Shixun Cao, Garry J. McIntyrea. 2019-01-07. Spin dynamics of edge-sharing spin chains in SrCa13Cu24O41. https://doi.org/10.1103/physrevb.98.184411

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