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arXiv 1901.02102cond-mat.str-el
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SrCa13Cu24O41中边共享自旋链的自旋动力学

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. Ga… 展开作者

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

摘要:

利用中子非弹性散射研究了高钙掺杂准一维磁体SrCa_(13)Cu_(24)O_(41)在磁有序态下的低能磁激发。我们观察到的无隙自旋波激发,色散沿a和c轴,但沿b轴非色散。这种激发归因于来自自旋链亚晶格的自旋波。模型拟合实验数据给出最近邻相互作用Jc为5.4 meV和链间相互作用Ja = 4.4 meV。Jc是反铁磁的,其值接近于类似的边共享自旋链系统,如CuGeO3的最近邻相互作用。与Sr_(14)Cu_(24)O_(41)中的空穴掺杂自旋链相比,SrCa_(13)Cu_(24)O_(41)中的自旋链表现为无隙激发,而Sr_(14)Cu_(24)O_(41)中的自旋链则表现为无隙激发。我们将这种从有隙激发到无隙激发的变化归因于Ca掺杂后空穴从链状亚晶格转移到梯形亚晶格。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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