Resonant and non-dissipative tunneling in independently contacted graphene structures

TL;DR

This paper models both dissipative and non-dissipative tunneling in independently contacted graphene layers separated by boron nitride, revealing conditions for resonant tunneling and its potential for transistor enhancement.

Contribution

It provides a theoretical analysis of resonant and non-dissipative tunneling regimes in graphene heterostructures, including current-voltage characteristics aligned with experiments.

Findings

Agreement of back-gated structure current-voltage with experiments

Resonant tunneling enhances response tenfold in double-gated structures

Identification of conditions for non-dissipative tunneling regimes

Abstract

The tunneling current between independently contacted graphene sheets separated by boron nitride insulator is calculated. Both dissipative tunneling transitions, with momentum transfer due to disorder scattering, and non-dissipative regime of tunneling, which appears due to intersection of electron and hole branches of energy spectrum, are described. Dependencies of tunneling current on concentrations in top and bottom graphene layers, which are governed by the voltages applied through independent contacts and gates, are considered for the back- and double-gated structures. The current-voltage characteristics of the back-gated structure are in agreement with the recent experiment [Science 335, 947 (2012)]. For the double-gated structures, the resonant dissipative tunneling causes a ten times enhancement of response which is important for transistor applications.