Tunneling Spectroscopy of Quantum Hall States in Bilayer Graphene PN Networks

TL;DR

This paper demonstrates controlled tunneling between quantum Hall edge states in bilayer graphene, revealing detailed spectroscopic insights and paving the way for advanced quantum electronic device engineering.

Contribution

It introduces a method to engineer and spectroscopically probe quantum Hall edge networks in bilayer graphene with high energy resolution, enabling new quantum device possibilities.

Findings

Resonant tunneling observed between co-propagating QH edges across defined barriers.

Spectroscopic measurements reveal spatial profile and density of states of QH edge states.

Engineered QH edge networks open avenues for future quantum electronic devices.

Abstract

Two dimensional electronic systems under strong magnetic field form quantum Hall (QH) edge states, which propagate along the boundary of a sample with a dissipationless current. Engineering the pathway of these propagating one-dimensional chiral modes enables the investigation of quantum tunneling between adjacent QH states. Here, we report tunneling transport in spatially controlled networks of QH edge states in bilayer graphene. We observe resonant tunneling between co-propagating QH edges across barriers formed by electrically defining incompressible strips. Employing spectroscopic tunneling measurements enable the direct probing of the spatial profile, density of states, and compressibility of the QH edge states with an unprecedented energy resolution. The capability to engineer the QH edge network provides an opportunity to build future quantum electronic devices supported by rich underline physics.