Transport Anisotropy in One-dimensional Graphene Superlattice in the High Kronig-Penney Potential Limit

Fuente: arXiv
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Main Authors: Li, Tianlin, Chen, Hanying, Wang, Kun, Hao, Yifei, Zhang, Le, Watanabe, Kenji, Taniguchi, Takashi, Hong, Xia
Format: Preprint
Published: 2023
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author Li, Tianlin
Chen, Hanying
Wang, Kun
Hao, Yifei
Zhang, Le
Watanabe, Kenji
Taniguchi, Takashi
Hong, Xia
author_facet Li, Tianlin
Chen, Hanying
Wang, Kun
Hao, Yifei
Zhang, Le
Watanabe, Kenji
Taniguchi, Takashi
Hong, Xia
contents One-dimensional graphene superlattice subjected to strong Kronig-Penney (KP) potential is promising for achieving electron lensing effect, while previous studies utilizing the modulated dielectric gates can only yield a moderate, spatially dispersed potential profile. Here, we realize high KP potential modulation of graphene via nanoscale ferroelectric domain gating. Graphene transistors are fabricated on PbZr$_{0.2}$Ti$_{0.8}$O$_{3}$ back-gates patterned with periodic, 100-200 nm wide stripe domains. Due to band reconstruction, the h-BN top-gating induces satellite Dirac points in samples with current along the superlattice vector $\hat{s}$, a feature absent in samples with current perpendicular to $\hat{s}$. The satellite Dirac point position scales with the superlattice period ($L$) as $\propto L^β$, with $β= -1.18 \pm 0.06$. These results can be well explained by the high KP potential scenario, with the Fermi velocity perpendicular to $\hat{s}$ quenched to about 1% of that for pristine graphene. Our study presents a promising material platform for realizing electron supercollimation and investigating flat band phenomena.
format Preprint
id arxiv_https___arxiv_org_abs_2309_04931
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Transport Anisotropy in One-dimensional Graphene Superlattice in the High Kronig-Penney Potential Limit
Li, Tianlin
Chen, Hanying
Wang, Kun
Hao, Yifei
Zhang, Le
Watanabe, Kenji
Taniguchi, Takashi
Hong, Xia
Mesoscale and Nanoscale Physics
Materials Science
One-dimensional graphene superlattice subjected to strong Kronig-Penney (KP) potential is promising for achieving electron lensing effect, while previous studies utilizing the modulated dielectric gates can only yield a moderate, spatially dispersed potential profile. Here, we realize high KP potential modulation of graphene via nanoscale ferroelectric domain gating. Graphene transistors are fabricated on PbZr$_{0.2}$Ti$_{0.8}$O$_{3}$ back-gates patterned with periodic, 100-200 nm wide stripe domains. Due to band reconstruction, the h-BN top-gating induces satellite Dirac points in samples with current along the superlattice vector $\hat{s}$, a feature absent in samples with current perpendicular to $\hat{s}$. The satellite Dirac point position scales with the superlattice period ($L$) as $\propto L^β$, with $β= -1.18 \pm 0.06$. These results can be well explained by the high KP potential scenario, with the Fermi velocity perpendicular to $\hat{s}$ quenched to about 1% of that for pristine graphene. Our study presents a promising material platform for realizing electron supercollimation and investigating flat band phenomena.
title Transport Anisotropy in One-dimensional Graphene Superlattice in the High Kronig-Penney Potential Limit
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2309.04931