Proximity-induced superconductivity in epitaxial topological insulator/graphene/gallium heterostructures

Cequn Li, Yi Fan Zhao, Alexander Vera, Omri Lesser, Hemian Yi, Shalini Kumari, Zijie Yan, Chengye Dong, Timothy Bowen, Ke Wang, Haiying Wang, Jessica L. Thompson, Kenji Watanabe, Takashi Taniguchi, Danielle Reifsnyder Hickey, Yuval Oreg, Joshua A. Robinson, Cui Zu Chang, Jun Zhu

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

The introduction of superconductivity to the Dirac surface states of a topological insulator leads to a topological superconductor, which may support topological quantum computing through Majorana zero modes1,2. The development of a scalable material platform is key to the realization of topological quantum computing3,4. Here we report on the growth and properties of high-quality (Bi,Sb)2Te3/graphene/gallium heterostructures. Our synthetic approach enables atomically sharp layers at both hetero-interfaces, which in turn promotes proximity-induced superconductivity that originates in the gallium film. A lithography-free, van der Waals tunnel junction is developed to perform transport tunnelling spectroscopy. We find a robust, proximity-induced superconducting gap formed in the Dirac surface states in 5–10 quintuple-layer (Bi,Sb)2Te3/graphene/gallium heterostructures. The presence of a single Abrikosov vortex, where the Majorana zero modes are expected to reside, manifests in discrete conductance changes. The present material platform opens up opportunities for understanding and harnessing the application potential of topological superconductivity.

Original languageEnglish (US)
Pages (from-to)570-575
Number of pages6
JournalNature Materials
Volume22
Issue number5
DOIs
StatePublished - May 2023

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Proximity-induced superconductivity in epitaxial topological insulator/graphene/gallium heterostructures'. Together they form a unique fingerprint.

Cite this