Field-induced exciton condensation in LaCoO3.
Field-induced exciton condensation in LaCoO3.
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DOI：
10.1038/srep30510
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发表时间：
2016-07-27
影响因子：
4.6
通讯作者：
Kuneš J
中科院分区：
文献类型：
--
作者：
Sotnikov A;Kuneš J
受最近在LaCoO_3中观察到的磁场诱导相变的启发，我们研究了外场对自旋态有序和激子凝聚的不稳定性的影响。我们表明，虽然在这两种情况下的过渡可以诱导由外部场，临界场的温度依赖性有相反的斜率。基于这一结果，我们认为，实验观测选择激子凝聚的情况。我们表明，这种凝聚是可能的，由于高流动性的中间自旋激发。相应的色散的估计的宽度是足够大的推翻原子多重态的顺序，并使中间自旋激发传播一个特定的波矢量的系统的最低激发。
Motivated by recent observation of magnetic field induced transition in LaCoO3 we study the effect of external field in systems close to instabilities towards spin-state ordering and exciton condensation. We show that, while in both cases the transition can be induced by an external field, temperature dependencies of the critical field have opposite slopes. Based on this result we argue that the experimental observations select the exciton condensation scenario. We show that such condensation is possible due to high mobility of the intermediate spin excitations. The estimated width of the corresponding dispersion is large enough to overrule the order of atomic multiplets and to make the intermediate spin excitation propagating with a specific wave vector the lowest excitation of the system.