Hierarchical spectral inhomogeneity in photoluminescence of a twisted MoSe2/WSe2 heterobilayer moiré superlattice revealed by hyperspectral mapping

Fuente: arXiv
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Main Authors: Ahmad, Nurul Fariha, Urano, Yuto, Watanabe, Kenji, Taniguchi, Takashi, Kozawa, Daichi, Kitaura, Ryo
Format: Preprint
Published: 2026
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author Ahmad, Nurul Fariha
Urano, Yuto
Watanabe, Kenji
Taniguchi, Takashi
Kozawa, Daichi
Kitaura, Ryo
author_facet Ahmad, Nurul Fariha
Urano, Yuto
Watanabe, Kenji
Taniguchi, Takashi
Kozawa, Daichi
Kitaura, Ryo
contents Low-temperature photoluminescence from MoSe2/WSe2 moire superlattice often consists of a broad interlayer emission background with dense, narrow peaks, making microscopic line-by-line assignment difficult. Here, we use hyperspectral photoluminescence mapping and peak-decomposition-free spectral analyses to determine how this spectral complexity is organized in space. A 20 x 20 map acquired with a 400 nm pitch reveals three dominant spectral families that form contiguous real-space domains. Feature-wise spatial correlation analysis and whole-spectrum similarity yield a characteristic micron-scale length of 1.27-2.05 um, all exceeding the 0.85 um optical spot size. At the same time, individual pixels retain a dense, multi-peak structure, implying an unresolved local spectral manifold below optical resolution. Correlations among centroid, dominant energy, asymmetry, width, entropy, sharp fraction, and roughness indicate that the micron-scale energy landscape and local manifold complexity can be statistically separated, while remaining correlated across the map, consistent with a hierarchical organization of the emission spectrum. These results establish hierarchical inhomogeneity as an organizing principle of MoSe2/WSe2 moire superlattice photoluminescence.
format Preprint
id arxiv_https___arxiv_org_abs_2604_16939
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Hierarchical spectral inhomogeneity in photoluminescence of a twisted MoSe2/WSe2 heterobilayer moiré superlattice revealed by hyperspectral mapping
Ahmad, Nurul Fariha
Urano, Yuto
Watanabe, Kenji
Taniguchi, Takashi
Kozawa, Daichi
Kitaura, Ryo
Materials Science
Mesoscale and Nanoscale Physics
Low-temperature photoluminescence from MoSe2/WSe2 moire superlattice often consists of a broad interlayer emission background with dense, narrow peaks, making microscopic line-by-line assignment difficult. Here, we use hyperspectral photoluminescence mapping and peak-decomposition-free spectral analyses to determine how this spectral complexity is organized in space. A 20 x 20 map acquired with a 400 nm pitch reveals three dominant spectral families that form contiguous real-space domains. Feature-wise spatial correlation analysis and whole-spectrum similarity yield a characteristic micron-scale length of 1.27-2.05 um, all exceeding the 0.85 um optical spot size. At the same time, individual pixels retain a dense, multi-peak structure, implying an unresolved local spectral manifold below optical resolution. Correlations among centroid, dominant energy, asymmetry, width, entropy, sharp fraction, and roughness indicate that the micron-scale energy landscape and local manifold complexity can be statistically separated, while remaining correlated across the map, consistent with a hierarchical organization of the emission spectrum. These results establish hierarchical inhomogeneity as an organizing principle of MoSe2/WSe2 moire superlattice photoluminescence.
title Hierarchical spectral inhomogeneity in photoluminescence of a twisted MoSe2/WSe2 heterobilayer moiré superlattice revealed by hyperspectral mapping
topic Materials Science
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2604.16939