Theory for Planar Hall Effect in Organic Dirac Fermion System

Abstract

In a recent experiment on the interlayer magnetoresistance in the quasi-two-dimensional organic salt, $\alpha$-(BEDT-TTF)${}_2$I${}_3$, it has been observed that at low temperatures, interlayer tunneling attains phase coherence, leading to the emergence of a three-dimensional electronic structure. Theoretically and experimentally it has been suggested that the system exhibits characteristics of a three-dimensional Dirac semimetal as a consequence of broken time-reversal symmetry and inversion symmetry. Here, we perform a theoretical calculation of the magnetoconductivity under an in-plane magnetic field and demonstrate that the system displays a planar Hall effect. Our calculations are based on a realistic model for $\alpha$-(BEDT-TTF)${}_2$I${}_3$ incorporating interlayer tunneling and the tilt of the Dirac cone. Given that the planar Hall effect is anticipated as a consequence of chiral anomaly, our findings provide support for the classification of $\alpha$-(BEDT-TTF)${}_2$I${}_3$ as a three-dimensional Dirac semimetal.

4 pages, 3 figures

References in corpus (4)

• Phase transition between the quantum spin Hall and insulator phases in 3D: emergence of a topological gapless phase
• Berry phase effect in anomalous thermoelectric transport
• Chiral anomaly and transport in Weyl metals
• Topological Surface States and Dirac point tuning in ternary Bi2Te2Se class of topological insulators