Quantum Hall effect in multilayered massless Dirac fermion systems with tilted cones

TL;DR

This study reports the first observation of quantum Hall effects and Shubnikov-de Haas oscillations in multilayered massless Dirac fermion systems with tilted cones, highlighting the role of interlayer correlations.

Contribution

It demonstrates the successful detection of QHE and SdH oscillations in multilayered Dirac fermion systems with tilted cones, emphasizing the importance of interlayer interactions.

Findings

Detection of SdH oscillations with Berry's phase π

Observation of quantized Hall resistance in multilayered system

Effective doping was limited to two layers

Abstract

We report the first observation of Shubnikov-de Haas (SdH) oscillations and quantized Hall resistance in the multilayered massless Dirac fermion system $\alpha$-(BEDT-TTF)$_2$I$_3$ with tilted cones. Holes were injected into the thin crystal fixed on a polyethylene naphthalate (PEN) substrate by contact electrification. The detection of SdH oscillations whose phase was modified by Berry's phase $\pi$ strongly suggested that the carrier doping was successful in this system. We succeeded in detecting the quantum Hall effect (QHE) with the steps which is the essence of two dimensional Dirac fermion systems. The number of effectively doped layers was examined to be two in this device. We reveal that the correlation between effective layers plays an important role in QHE.