Gap opening mechanism for correlated Dirac electrons in organic compounds alpha-(BEDT-TTF)2I3 and alpha-(BEDT-TSeF)2I3

Article

关键词: SPIN;    CONDUCTOR;    TRANSPORT;    FERMIONS;    ABSENCE;    MODEL;   

DOI  :  10.1103/PhysRevB.107.L041108

来源: SCIE

【 摘 要 】

To determine how electron correlations open a gap in two-dimensional massless Dirac electrons in the organic compounds alpha-(BEDT-TTF)2I3 [alpha-(ET)2I3] and alpha-(BEDT-TSeF)2I3 [alpha-(BETS)2I3], we derive and analyze ab initio low-energy effective Hamiltonians for these two compounds. We find that the horizontal stripe charge ordering opens a gap in the massless Dirac electrons in alpha-(ET)2I3, while an insulating phase without explicit symmetry breaking appears in alpha-(BETS)2I3. We clarify that a combination of anisotropic transfer integrals and electron correlations induces a dimensional reduction in the spin correlations, i.e., one-dimensional spin correlations develop in alpha-(BETS)2I3. We show that one-dimensional spin correlations open a gap in the massless Dirac electrons. Our finding paves the way for opening gaps for massless Dirac electrons using strong electron correlations.

【 授权许可】

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