Manipulating chiral transmission by gate geometry: switching in graphene with transmission gaps

TL;DR

This paper demonstrates a graphene-based electronic switch that uses gate geometry to manipulate chiral electron transmission, creating a tunable transmission gap for low-energy switching without structural band-gap reduction.

Contribution

It introduces a novel method of switching in graphene via gate-controlled chiral transmission gaps, enabling subthermal energy consumption and high tunability.

Findings

Device resistance increases by orders of magnitude in bipolar doping regime.

Switching is achieved through a transmission gap without reducing conduction channels.

Subthermal turn-on surpasses the Landauer limit on switching energy.

Abstract

We explore the chiral transmission of electrons across graphene heterojunctions for electronic switching using gate geometry alone. A sequence of gates is used to collimate and orthogonalize the chiral transmission lobes across multiple junctions, resulting in negligible overall current. The resistance of the device is enhanced by several orders of magnitude by biasing the gates into the bipolar $npn$ doping regime, as the ON state in the near homogeneous $nn^-n$ regime remains highly conductive. The mobility is preserved because the switching involves a transmission gap instead of a structural band-gap that would reduce the number of available channels of conduction. Under certain conditions this transmission gap is highly gate tunable, allowing a subthermal turn-on that beats the Landauer bound on switching energy limiting present day digital electronics.