Anisotropy of Dirac cones and Van Hove singularity in an organic Dirac fermion system

Article

关键词: ALPHA-(BEDT-TTF)(2)I-3;    SUPERCONDUCTIVITY;    CONDUCTOR;    PRESSURE;    METAL;   

DOI  :  10.1103/PhysRevB.99.035106

来源: SCIE

【 摘 要 】

We propose an experimental method to examine the in-plane anisotropy of electronic structure in layered conductors. In the method, we measure the interlayer magnetoresistance as a function of in-plane magnetic field orientation. We applied it to an organic Dirac fermion system alpha-(BEDT-TTF)(2)I-3 to experimentally determine the orientation of the anisotropic Dirac cones. It is concluded that the long axis of the elliptic constant-energy contours of the Dirac cone is tilted by approximately -30 degrees from the crystalline a axis to the b axis under hydrostatic pressures. Additionally, we observed a signature of Van Hove singularity (which is a saddle point of the band dispersion) at 30-40 K above or below the Dirac point. The ridgeline of the saddle point is estimated as almost parallel to the crystalline b axis.

【 授权许可】

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