Gateable edge supercurrent in a hybrid graphene/TaS₂ device

Cheng-Yuan Huang^1,2*, Yi-Yiao Lo⁴, Takashi Taniguchi³, Kenji Watanabe³, Raman Sankar², Ya-Ping Chiu¹, Chung-Ting Ke²

¹Department of Physics, National Taiwan University, Taipei, Taiwan
²Institute of Physics, Academia Sinica, Taipei, Taiwan
³National Institute for Materials Science, Tsukuba, Japan
⁴National Chengchi University, Taipei, Taiwan

* Presenter:Cheng-Yuan Huang, email:s963037@gmail.com

The superconducting proximity effect enables superconducting correlations to penetrate a neighboring normal material, giving rise to exotic quantum phenomena such as p-wave–like pairing. Here, we investigate the superconducting proximity effect in a van der Waals heterostructure by combining a 2H-TaS₂ superconductor [1] (Tc = 2.2 K) with monolayer graphene. To ensure an atomically clean interface, the h-BN/graphene/TaS₂ stack was assembled in an inert atmosphere, with the h-BN layer protecting the materials during fabrication. Cooling the device down to millikelvin reveals a robust supercurrent traversing the hybrid region, which can be continuously tuned by electrostatic gating and magnetic field. In the high-gate-voltage regime, an interference pattern emerges whose periodicity is determined by the hybrid area, indicating the presence of edge-mode supercurrents. This behavior is consistent with the Little–Parks effect, signifying the formation of edge states in the hybrid system. Our findings demonstrate a new approach to realizing gate-tunable edge supercurrent in a graphene/TaS₂ platform, broadening the prospects for proximity-induced superconductivity in two-dimensional hybrid materials.

Keywords: Proximity effect, Graphene, Superconductor, Interference pattern, Little-Parks effect