Topological Surface Superconductivity via Josephson Coupling in Bi <sub>2</sub> Te <sub>3</sub> /Nb
Since discoveries of protected conducting surface states, topological superconducting qubits have enchanted quantum science as prime elements in future fault-tolerant devices, particularly those based on Josephson junctions containing topological insulators. Still, Josephson coupling is often eclipsed by other proximity effects that can dilute topological superconducting pairing at the nontrivial insulator's boundaries. Here, however, using an ultra-low-temperature scanning tunneling microscope, we detect Josephson physics in topological Bi<sub>2</sub>Te<sub>3</sub> films on superconducting Nb. At low temperatures, a previously undetected proximity gap varies little with Bi<sub>2</sub>Te<sub>3</sub> thickness and the density of states exhibits normal and superconducting components. Such observations are rationalized via Josephson pair tunneling through the (nearly) insulating Bi<sub>2</sub>Te<sub>3</sub> bulk, creating a rare, pure topological superconducting sheet. Our findings establish routes toward accessible topological superconducting states in qubits.
Authors
- T.‐C. Chiang (ORCID: https://orcid.org/0000-0001-7118-8299)
- Syu‐You Guan (ORCID: https://orcid.org/0000-0002-1855-252X)
- Meng-Kai Lin (ORCID: https://orcid.org/0000-0002-8713-3230)
- J. N. Eckstein (ORCID: https://orcid.org/0000-0002-3018-8863)
- Ro-Ya Liu (ORCID: https://orcid.org/0000-0003-2459-8556)
- Yang Bai (ORCID: https://orcid.org/0000-0002-2325-9467)
- Sung‐Kwan Mo (ORCID: https://orcid.org/0000-0003-0711-8514)
- David Flötotto
- Shujie Tang (ORCID: https://orcid.org/0000-0002-3511-8215)
- Yen-Chen Tsui
- Soorya Suresh Babu (ORCID: https://orcid.org/0000-0002-0037-7233)
- Jinwoong Hwang (ORCID: https://orcid.org/0000-0002-9272-5257)
- Peter Abbamonte (ORCID: https://orcid.org/0000-0003-1109-1510)
- Joseph A. Hlevyack (ORCID: https://orcid.org/0000-0001-7057-9335)
- Tien-Ming Chuang (ORCID: https://orcid.org/0000-0002-4524-1380)
- Yao Li (ORCID: https://orcid.org/0000-0002-9728-5035)
- Chengwei Wang (ORCID: https://orcid.org/0000-0002-7425-1334)
- Wenyu Chen (ORCID: https://orcid.org/0000-0003-2610-3342)
- Peng Chen (ORCID: https://orcid.org/0000-0003-1194-2119)
- Ji‐Eun Lee (ORCID: https://orcid.org/0009-0000-1510-0571)
Institutions
- Lawrence Berkeley National Laboratory (US)
- University of Illinois Urbana-Champaign (US)
- Kangwon National University (KR)
- Shanghai Jiao Tong University (CN)
- Chinese Academy of Sciences (CN)
- National Central University (TW)
- National Synchrotron Radiation Research Center (TW)
- Ministry of Education (IR)
- Institute of Physics, Academia Sinica (TW)
- Shanghai Institute of Microsystem and Information Technology (CN)
- Advanced Light Source
Publication Details
- Journal
- Nano Letters
- Published
- 2025-11-08
- DOI
- https://doi.org/10.1021/acs.nanolett.5c04230
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00