# Semimetallic features in quantum transport through a gate-defined point contact in bilayer graphene

## TL;DR

This paper reveals that a gate-defined quantum wire in bilayer graphene can exhibit semimetallic behavior at conduction onset, characterized by multiple minivalleys and an $8e^2/h$ conductance feature, due to its unique subband structure.

## Contribution

It introduces the concept of semimetallic features in quantum transport through a gate-defined bilayer graphene wire, highlighting the role of minivalley dispersion and subband degeneracy.

## Key findings

- Presence of an $8e^2/h$ conductance step at conduction threshold.
- Resonance peaks on the conductance plateau indicating semimetallic behavior.
- Multiple minivalleys in the lowest subband spectrum.

## Abstract

We demonstrate that, at the onset of conduction, an electrostatically defined quantum wire in bilayer graphene (BLG) with an interlayer asymmetry gap may act as a 1D semimetal, due to the multiple minivalley dispersion of its lowest subband. Formation of a non-monotonic subband coincides with a near-degeneracy between the bottom edges of the lowest two subbands in the wire spectrum, suggesting an $8e^2/h$ step at the conduction threshold, and the semimetallic behaviour of the lowest subband in the wire would be manifest as resonance transmission peaks on an $8e^2/h$ conductance plateau.