Charge Fractionalization in Artificial Tomonaga-Luttinger Liquids with Controlled Interaction Strength

TL;DR

This study demonstrates controllable charge fractionalization in artificial Tomonaga-Luttinger liquids created from coupled quantum Hall edge channels in graphene, with interaction strength tuned by channel separation, aligning with theoretical predictions.

Contribution

It introduces a method to control interaction strength in artificial TLLs via channel separation and verifies theoretical relations between fractionalization ratio and mode velocity.

Findings

Fractionalization ratio r varies with channel separation W.

Mode velocity v depends on W and matches TLL theory predictions.

Charged wavepackets reflect multiple times within the TLL region.

Abstract

We investigate charge fractionalizations in artificial Tomonaga-Luttinger liquids (TLLs) composed of two capacitively coupled quantum Hall edge channels (ECs) in graphene. The interaction strength of the artificial TLLs can be controlled through distance W between the ECs. We show that the fractionalization ratio r and the TLL mode velocity v vary with W. The experimentally obtained relation between v and r follows a unique function predicted by the TLL theory. We also show that charged wavepackets are reflected back and forth multiple times at both ends of the TLL region.