Abstract
In this manuscript, we explore tunnel spectroscopy of insulating barrier YBCO tunnel junctions fabricated with focused helium ion irradiation. Five junctions with different tunneling conductance were measured in a dilution refrigerator at temperatures between 50 and 800 millikelvin. The differential conductance of all devices exhibited an oscillation that was periodic with bias current with a period of about one micro amp. This feature was reproduced in all devices tested. We attribute this behavior to resonant tunneling sates above the energy gap.
| Original language | English |
|---|---|
| Article number | 7200104 |
| Journal | IEEE Transactions on Applied Superconductivity |
| Volume | 35 |
| Issue number | 5 |
| DOIs | |
| State | Published - 2025 |
Funding
Special thanks to Bob Dynes for insights into tunneling, Dr. Ilkeun Lee for logistical support, and the Sandia IBL team Ed Bielejek, Alex Belianov, and MichaelTitze for technical support. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE)Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly-owned subsidiary of Honeywell International, Inc., for the U.S. DOE's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government. This workwas supported in part by NNSA Minority Serving Institutions Partnership Program under Award DE-NA0004106 and in part by AFOSR under Grant FA9550-23-1-0369. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly-owned subsidiary of Honeywell International, Inc., for the U.S. DOE\u2019s National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the article do not necessarily represent the views of the U.S. DOE or the United States Government. This paper is based upon work supported by the NNSA Minority Serving Institutions Partnership Program under Award DE-NA0004106 and AFOSR grant FA9550-23-1-0369.
Keywords
- High Tc
- YBCO
- low-temperature transport characteristics
- planar junctions
- superconducting energy gap
- tunnel spectroscopy