60 citations · 303 across the 19 of their papers we have counts for
20 papers
Structures of iron and cobalt bimetallic clusters for optimized chemical vapor deposition growth of single-walled carbon nanotubes
Qingmei Hu, Daniel Hedman, Ya Feng +17
We investigate iron-cobalt (Fe-Co) alloys as a representative high-performance catalyst system for SWCNT growth in a systematic manner by combining chemical vapor deposition (CVD)…
Robust chirality memory in carbon nanotubes growing under modulated and evolving environments
K. Otsuka, R. Fujiwara, S. Maruyama
Controlling the chirality and yield of carbon nanotubes is essential for their diverse applications from macroscopic composites to nanoelectronics. Floating-catalyst chemical vapor…
Analysis of Fe and Co binary catalysts in chemical vapor deposition growth of single-walled carbon nanotubes
Qingmei Hu, Ya Feng, Wanyu Dai +17
Metal catalysts play a pivotal role in the growth of single-walled carbon nanotubes (SWCNTs), with binary metallic catalysts emerging as an efficient SWCNT synthesis strategy. Amon…
Metallic NbS2 one-dimensional van der Waals heterostructures
Wanyu Dai, Yongjia Zheng, Akihito Kumamoto +12
This study presents the experimental realization of metallic NbS2-based one-dimensional van der Waals heterostructures applying a modified NaCl-assisted chemical vapor deposition a…
Catalyst-mediated etching of carbon nanotubes exhibiting electronic-structure insensitivity and reciprocal kinetics with growth
K. Otsuka, S. Maruyama
The selective etching of carbon nanotubes has been widely explored as a post-synthetic route for enriching semiconducting species. As nanoelectronic applications increasingly deman…
Machine-Learned Bond-Order Potential for Exploring the Configuration Space of Carbon
Ikuma Kohata, Kaoru Hisama, Keigo Otsuka +1
Construction of transferable machine-learning interatomic potentials with a minimal number of parameters is important for their general applicability. Here, we present a machine-le…
Low-Temperature Synthesis of Weakly Confined Carbyne inside Single-Walled Carbon Nanotubes
Bo-Wen Zhang, Xi-Yang Qiu, Yicheng Ma +16
Carbyne, a one-dimensional (1D) carbon allotrope with alternating triple and single bonds, has the highest known mechanical strength but is unstable to bending, limiting synthesis…
Resonant exciton transfer in mixed-dimensional heterostructures for overcoming dimensional restrictions in optical processes
N. Fang, D. Yamashita, S. Fujii +8
Nanomaterials exhibit unique optical phenomena, in particular excitonic quantum processes occurring at room temperature. The low dimensionality, however, imposes strict requirement…
Edge Dynamics in Iron-Cluster Catalyzed Growth of Single-Walled Carbon Nanotubes Revealed by Molecular Dynamics Simulations based on a Neural Network Potential
Ikuma Kohata, Ryo Yoshikawa, Kaoru Hisama +3
Given the high potential for applications utilizing the unique properties of single-walled carbon nanotubes (SWCNTs), there is considerable enthusiasm for addressing the challenges…
Quantization of mode shifts in nanocavities integrated with atomically thin sheets
N. Fang, D. Yamashita, S. Fujii +5
The unique optical properties of two-dimensional layered materials are attractive for achieving increased functionality in integrated photonics. Owing to the van der Waals nature,…
Universal map of gas-dependent kinetic selectivity in carbon nanotube growth
K. Otsuka, R. Ishimaru, A. Kobayashi +5
Single-walled carbon nanotubes have been a candidate for outperforming silicon in ultrascaled transistors, but the realization of nanotube-based integrated circuits requires dense…
One-dimensional van der Waals Heterostructures: Growth Mechanism and Handedness Correlation Revealed by Non-destructive TEM
Yongjia Zheng, Akihito Kumamoto, Kaoru Hisama +15
In this work, we perform a follow-up and comprehensive study on the structural details and formation mechanism of chemical vapor deposition (CVD) synthesized one-dimensional (1D) v…
Nanotube-based one-dimensional heterostructures coupled by van der Waals forces
Sofie Cambré, Ming Liu, Dmitry Levshov +3
One-dimensional (1D) van der Waals heterostructures based on carbon nanotube templates are raising a lot of excitement due to the possibility of creating new optical and electronic…
Quantum emission assisted by energy landscape modification in pentacene-decorated carbon nanotubes
Zhen Li, Keigo Otsuka, Daiki Yamashita +2
Photoluminescent carbon nanotubes are expected to become versatile room-temperature single-photon sources that have applications in quantum information processing. Quantum emission…
Formation of Organic Color Centers in Air-Suspended Carbon Nanotubes Using Vapor-Phase Reaction
D. Kozawa, X. Wu, A. Ishii +7
Organic color centers in single-walled carbon nanotubes have demonstrated exceptional ability to generate single photons at room temperature in the telecom range. Combining the col…
Waveguide coupled cavity-enhanced light emission from individual carbon nanotubes
D. Yamashita, H. Machiya, K. Otsuka +2
We demonstrate an individual single-walled carbon nanotube light emitter integrated onto a microcavity and a waveguide operating in the telecom wavelength regime. Light emission fr…
Deterministic transfer of optical-quality carbon nanotubes for atomically defined technology
K. Otsuka, N. Fang, D. Yamashita +3
When continued device scaling reaches the ultimate limit imposed by atoms, technology based on atomically precise structures is expected to emerge. Device fabrication will then req…
Hexagonal boron nitride as an ideal substrate for carbon nanotube photonics
N. Fang, K. Otsuka, A. Ishii +4
Hexagonal boron nitride is widely used as a substrate for two-dimensional materials in both electronic and photonic devices. Here, we demonstrate that two-dimensional hexagonal bor…
Super-Resolution Fluorescence Imaging of Carbon Nanotubes Using a Nonlinear Excitonic Process
K. Otsuka, A. Ishii, Y. K. Kato
Highly efficient exciton-exciton annihilation process unique to one-dimensional systems is utilized for super-resolution imaging of air-suspended carbon nanotubes. Through the comp…
Organic molecular tuning of many-body interaction energies in air-suspended carbon nanotubes
S. Tanaka, K. Otsuka, K. Kimura +4
We investigate adsorption effects of copper phthalocyanine molecules on excitons and trions in air-suspended carbon nanotubes. Using photoluminescence excitation spectroscopy, we o…