The electronic structure of weak charge-ordering (CO) state just below the critical pressure in an organic conductor α-(BEDT-TTF)₂I₃ was experimentally investigated using peak structure in the temperature dependence of interlayer magnetoresistance (MR). Based on a minimal model considering multiple Landau levels (LLs), we discuss herein the MR peak as characteristic to multilayer massless/massive Dirac fermion (DF) systems. MR measured in the weak CO state exhibited a clear MR peak, and its magnetic-field dependence was consistent with the LL behavior of a massive DF with a small gap. Results indicate that the weak CO state in α-(BEDT-TTF)₂I₃ is a massive DF state.

中文翻译：

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α-（BEDT-TTF）2I3中弱电荷有序状态的大量狄拉克费米子的实验确认

在层间磁阻（MR）的温度依赖性中，使用峰结构对有机导体α-（BEDT-TTF）₂ I ₃的临界电荷以下的电子结构进行了实验研究。基于考虑了多个朗道能级（LLs）的最小模型，我们在此讨论MR峰作为多层无质量/大规模狄拉克费米子（DF）系统的特征。在弱CO状态下测量的MR表现出清晰的MR峰，并且其磁场依赖性与具有小间隙的大型DF的LL行为一致。结果表明，α-（BEDT-TTF）₂ I ₃中的弱CO态为块状DF态。