Inter-Band Effects of Magnetic Field on Hall Conductivity in Multi Layered Massless Dirac Fermion System $\alpha$-(BEDT-TTF)$_2$I$_3$

TL;DR

This paper investigates the effects of magnetic fields on Hall conductivity in a layered massless Dirac fermion system, revealing how chemical potential variations influence inter-band phenomena in a novel zero-gap organic material.

Contribution

It demonstrates the inter-band effects of magnetic fields on Hall conductivity in $ ext{α}$-(BEDT-TTF)$_2$I$_3$, highlighting the role of chemical potential near Dirac points in a new zero-gap material.

Findings

Detection of inter-band effects of magnetic field on Hall conductivity.

Revealed temperature dependence of chemical potential in the material.

Established the experimental formula for chemical potential.

Abstract

We have discovered two-dimensional zero-gap material with a layered structure in the organic conductor $\alpha$-(BEDT-TTF)$_2$I$_3$ under high hydrostatic pressure. In contrast to graphene, the electron-hole symmetry is not good except at the vicinity of the Dirac points. Thus, temperature dependence of the chemical potential, $\mu$, plays an important role in the transport in this system. The experimental formula of $\mu$ is revealed. We succeeded in detecting the inter-band effects of a magnetic field on the Hall conductivity when $\mu$ passes the Dirac point.