Scalable fabrication of graphene nanoribbon quantum dot devices with stable orbital-level spacing

Toshiaki Kato, Takahito Kitada, Mizuki Seo, Wakana Okita, Naofumi Sato, Motoya Shinozaki, Takaya Abe, Takeshi Kumasaka, Takumi Aizawa, Yui Muto, Toshiro Kaneko, Tomohiro Otsuka

Research output: Contribution to journalArticlepeer-review

Abstract

Large-scale integration of quantum-dot devices is essential for realizing various quantum devices. Graphene-based quantum dots provide a promising platform for spin qubits because of their low nuclear spin density and weak spin-orbit interaction. However, the integration of graphene-based quantum dots remains a challenge. Here, we demonstrate the scalable fabrication of graphene nanoribbon-based quantum-dot devices using a nickel nanobar technique. Fine structures formed in the middle of the nanoribbons exhibit quantum-dot behavior, and more than 56% of devices fabricated on the same substrate show Coulomb diamond features, indicating that large-scale integration of graphene nanoribbon quantum-dot devices is possible with our method. Cryogenic measurements reveal orbital-level spacings between the ground and excited states that are stable up to high-temperature conditions of ~20 K. We explain this stability in terms of the very fine structures formed in the middle of the nanoribbons and their relatively low effective mass.

Original languageEnglish
Article number103
JournalCommunications Materials
Volume3
Issue number1
DOIs
Publication statusPublished - 2022 Dec

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials

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