Theory of excitonic states in CaB6

Article

关键词: 2ND-HARMONIC GENERATION;    ANTIFERROMAGNETIC CR2O3;    FERROMAGNETISM;    CA1-XLAXB6;    SPECTROSCOPY;    HEXABORIDES;    ELECTRON;    CRYSTALS;    ORDER;   

DOI  :  10.1103/PhysRevB.66.184405

来源: SCIE

【 摘 要 】

We study the excitonic states in CaB6 in terms of the Ginzburg-Landau theory. By minimizing the free energy and by comparing with experimental results, we identify two possible ground states with exciton condensation. They both break time-reversal and inversion symmetries. This leads to various magnetic and optical properties. As for magnetic properties, the compound is expected to be an antiferromagnet, and its spin structure is predicted. It will exhibit the magnetoelectric effect, and observed ferromagnetism in doped samples and in thin-film and powder samples can arise from this effect. Interesting optical phenomena such as the nonreciprocal optical effect and the second-harmonic generation are predicted. Their measurement for CaB6 will clarify whether exciton condensation occurs or not and which of the two states is realized.

【 授权许可】

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