日本Wako RIKEN新兴物质科学中心Tetsuo Hanaguri团队研究了石墨烯单层NbSe₂中扭曲角控制的超导电性。相关论文于2025年3月20日发表在《自然—物理学》杂志上。

超导性是非平凡量子现象和器件的基础，但它们通常需要人工控制超导能隙。在真实空间中，有多种方法可以调整超导间隙，例如引入界面和缺陷。然而，在动量空间中操纵超导能隙具有挑战性。

研究组证明了通过改变层之间的扭曲角，可以在特定时刻改变石墨烯上NbSe₂单层的超导能隙。他们基于光谱成像的扫描隧道显微镜实验揭示了Bogoliubov准粒子相对于NbSe₂和石墨烯晶格扭曲的干涉图案。结果发现，这些手性干涉图案起源于动量空间中扭曲相关的六重区域，其中NbSe₂单层和石墨烯的费米表面重叠。这一发现不仅拓宽了人们对扭曲双层系统中超导性的理解，也为设计具有可调特性的人造超导材料和器件开辟了可能性。

附：英文原文

Title: Superconductivity controlled by twist angle in monolayer NbSe2 on graphene

Author: Naritsuka, Masahiro, Machida, Tadashi, Asano, Shun, Yanase, Youichi, Hanaguri, Tetsuo

Issue&Volume: 2025-03-20

Abstract: Superconductivity serves as a basis for non-trivial quantum phenomena and devices, but they often require artificial control of the superconducting gap. In real space, there are various ways to tailor the superconducting gap, such as by introducing interfaces and defects. However, it is challenging to manipulate the superconducting gap in momentum space. Here we demonstrate that the superconducting gap of NbSe2 monolayers on graphene can be modified at specific momenta by changing the twist angle between the layers. Our spectroscopic-imaging-based scanning tunnelling microscopy experiments reveal the interference patterns of Bogoliubov quasiparticles that are twisted with respect to NbSe2 and graphene lattices. We find that these chiral interference patterns originate from the twist-dependent sextet of regions in momentum space in which the Fermi surfaces of the NbSe2 monolayer and graphene overlap. This finding not only broadens our understanding of superconductivity in twisted bilayer systems but also opens up possibilities for designing artificial superconducting materials and devices with tunable properties.

DOI: 10.1038/s41567-025-02828-6

Source: https://www.nature.com/articles/s41567-025-02828-6