Transport Properties through Double Barrier Structure in Graphene

TL;DR

This paper investigates how relativistic Dirac fermions transmit through a graphene double barrier, revealing insights into transport properties and showing that certain conductance features are unaffected by potential ratios.

Contribution

It provides a systematic analysis of transport in graphene double barriers, including the reduction to a 1D Dirac problem and the insensitivity of minimal conductivity and Fano factor to potential ratios.

Findings

Transmission depends on barrier parameters and mode

Reduction to 1D Dirac equation under specific conditions

Minimal conductivity and Fano factor are ratio-insensitive

Abstract

The mode-dependent transmission of relativistic ballistic massless Dirac fermion through a graphene based double barrier structure is being investigated for various barrier parameters. We compare our results with already published work and point out the relevance of these findings to a systematic study of the transport properties in double barrier structures. An interesting situation arises when we set the potential in the leads to zero, then our 2D problem reduces effectively to a 1D massive Dirac equation with an effective mass proportional to the quantized wave number along the transverse direction. Furthermore we have shown that the minimal conductivity and maximal Fano factor remain insensitive to the ratio between the two potentials V_2/V_1=\alpha.