Yang Jixiang, Shi Xiaoyan, Ye Shenyong, Yoon Chiho, Lu Zhengguang, Kakani Vivek, Han Tonghang, Seo Junseok, Shi Lihan, Watanabe Kenji, Taniguchi Takashi, Zhang Fan, Ju Long
Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
Department of Physics, The University of Texas at Dallas, Richardson, TX, USA.
Nat Mater. 2025 Mar 19. doi: 10.1038/s41563-025-02156-3.
Spin-orbit coupling (SOC) has played an important role in many topological and correlated electron materials. In graphene-based systems, SOC induced by a transition metal dichalcogenide at close proximity has been shown to drive topological states and strengthen superconductivity. However, in rhombohedral multilayer graphene, a robust platform for electron correlation and topology, superconductivity and the role of SOC remain largely unexplored. Here we report transport measurements of transition metal dichalcogenide-proximitized rhombohedral trilayer graphene. We observed a hole-doped superconducting state SC4 with a critical temperature of 234 mK. On the electron-doped side, we noted an isospin-symmetry-breaking three-quarter-metal phase and observed that the nearby weak superconducting state SC3 is substantially enhanced. Surprisingly, the original superconducting state SC1 in bare rhombohedral trilayer graphene is strongly suppressed in the presence of transition metal dichalcogenide-opposite to the effect of SOC on all other graphene superconductivities. Our observations form the basis of exploring superconductivity and non-Abelian quasiparticles in rhombohedral graphene devices.
自旋轨道耦合（SOC）在许多拓扑和关联电子材料中发挥了重要作用。在基于石墨烯的体系中，由紧邻的过渡金属二硫属化物诱导的SOC已被证明能驱动拓扑态并增强超导性。然而，在菱方多层石墨烯中，这个用于电子关联和拓扑的强大平台，超导性以及SOC的作用在很大程度上仍未被探索。在此，我们报告了对过渡金属二硫属化物近邻的菱方三层石墨烯的输运测量。我们观察到一个临界温度为234 mK的空穴掺杂超导态SC4。在电子掺杂侧，我们注意到一个同位旋对称性破缺的四分之三金属相，并观察到附近的弱超导态SC3显著增强。令人惊讶的是，在存在过渡金属二硫属化物的情况下，裸菱方三层石墨烯中的原始超导态SC1被强烈抑制——这与SOC对所有其他石墨烯超导性的影响相反。我们的观察结果构成了探索菱方石墨烯器件中超导性和非阿贝尔准粒子的基础。
