Evidence for electron localisation in a moiré-of-moiré superlattice

Fuente: arXiv
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Main Authors: Park, Hangyeol, Oh, Junhyeok, Ghadimi, Rasoul, Mondal, Chiranjit, Jeong, Yungi, Choi, Won Beom, Watanabe, Kenji, Taniguchi, Takashi, Yang, Bohm-Jung, Jang, Joonho
Format: Preprint
Published: 2025
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author Park, Hangyeol
Oh, Junhyeok
Ghadimi, Rasoul
Mondal, Chiranjit
Jeong, Yungi
Choi, Won Beom
Watanabe, Kenji
Taniguchi, Takashi
Yang, Bohm-Jung
Jang, Joonho
author_facet Park, Hangyeol
Oh, Junhyeok
Ghadimi, Rasoul
Mondal, Chiranjit
Jeong, Yungi
Choi, Won Beom
Watanabe, Kenji
Taniguchi, Takashi
Yang, Bohm-Jung
Jang, Joonho
contents The localisation of electrons in a lattice potential is an quantum-mechanical phenomenon and is often associated with remarkable physical properties of solids involving electron spins, electric polarisations and topological effects. In particular, even a small amount of distortion of the lattice potential can localise otherwise-delocalised quantum states in low-dimensional electron systems, dramatically influencing their thermodynamic properties and charge-transport behaviour. Study of such electron localisation induced by an aperiodic lattice potential remains exceptionally challenging in solid-state systems, since extrinsic disorders can trivially trap electrons in potential minima near disorders, obscuring the underlying quantum-mechanical origin of localisation phenomena. Van der Waals heterostructures can provide an alternative route for explorations of the phenomena via the emergence of superlattice potentials generated by rotating and stacking individual layers. Here, we report strong signatures of electron localisation in helical trilayer graphene, where the interplay of two moiré patterns gives rise to a moiré-of-moiré superlattice with distinct regions of moiré-periodic and moiré-aperiodic potentials. Remarkably, our measurements reveal the presence of double moiré-induced bands and high-order Brown-Zak oscillations, which are direct reflections of the periodic region with two constituent moiré patterns, and a superimposed anomalous hysteretic signal attributable to the aperiodic region. The data strongly suggest that electron wave functions are partially localised driven by the loss of a periodic lattice potential. Our work provides insight into the effects of spatially inhomogeneous lattice potentials on the low-dimensional electronic states and introduces a promising approach to control electron localisation for practical applications in solid-state devices.
format Preprint
id arxiv_https___arxiv_org_abs_2511_22115
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Evidence for electron localisation in a moiré-of-moiré superlattice
Park, Hangyeol
Oh, Junhyeok
Ghadimi, Rasoul
Mondal, Chiranjit
Jeong, Yungi
Choi, Won Beom
Watanabe, Kenji
Taniguchi, Takashi
Yang, Bohm-Jung
Jang, Joonho
Mesoscale and Nanoscale Physics
The localisation of electrons in a lattice potential is an quantum-mechanical phenomenon and is often associated with remarkable physical properties of solids involving electron spins, electric polarisations and topological effects. In particular, even a small amount of distortion of the lattice potential can localise otherwise-delocalised quantum states in low-dimensional electron systems, dramatically influencing their thermodynamic properties and charge-transport behaviour. Study of such electron localisation induced by an aperiodic lattice potential remains exceptionally challenging in solid-state systems, since extrinsic disorders can trivially trap electrons in potential minima near disorders, obscuring the underlying quantum-mechanical origin of localisation phenomena. Van der Waals heterostructures can provide an alternative route for explorations of the phenomena via the emergence of superlattice potentials generated by rotating and stacking individual layers. Here, we report strong signatures of electron localisation in helical trilayer graphene, where the interplay of two moiré patterns gives rise to a moiré-of-moiré superlattice with distinct regions of moiré-periodic and moiré-aperiodic potentials. Remarkably, our measurements reveal the presence of double moiré-induced bands and high-order Brown-Zak oscillations, which are direct reflections of the periodic region with two constituent moiré patterns, and a superimposed anomalous hysteretic signal attributable to the aperiodic region. The data strongly suggest that electron wave functions are partially localised driven by the loss of a periodic lattice potential. Our work provides insight into the effects of spatially inhomogeneous lattice potentials on the low-dimensional electronic states and introduces a promising approach to control electron localisation for practical applications in solid-state devices.
title Evidence for electron localisation in a moiré-of-moiré superlattice
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2511.22115