Selective Manipulation and Tunneling Spectroscopy of Broken-Symmetry Quantum Hall States in a Hybrid-edge Quantum Point Contact

TL;DR

This paper introduces a hybrid-edge quantum point contact device in graphene, enabling precise control and spectroscopy of broken-symmetry quantum Hall states, revealing detailed energy gaps and state interactions.

Contribution

It presents a novel device architecture allowing selective manipulation and high-resolution tunneling spectroscopy of symmetry-broken quantum Hall states in graphene.

Findings

Controlled hybridization of quantum Hall states demonstrated

High-resolution measurement of energy gaps (~0.1 meV) achieved

Electrostatic control over quantum state coupling improved

Abstract

We present a device architecture of hybrid-edge and dual-gated quantum point contact. We demonstrate improved electrostatic control over the separation, position, and coupling of each broken-symmetry compressible strip in graphene. Via low-temperature magneto-transport measurement, we demonstrate selective manipulation over the evolution, hybridization, and transmission of arbitrarily chosen quantum Hall states in the channel. With gate-tunable tunneling spectroscopy, we characterize the energy gap of each symmetry-broken quantum Hall state with high resolution on the order of ~0.1 meV.