Tomasch Oscillations as Above-Gap Signature of Topological Superconductivity

Scientific paper - Original scientific paper

• Author: Antonio Štrkalj
• Author: Xi-Rong Chen
• Author: Wei Chen
• Author: D. Y. Xing
• Author: Oded Zilberberg
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The identification of topological superconductors usually involves searching for in-gap modes that are protected by topology. However, in current experimental settings, the smoking-gun evidence of these in-gap modes is still lacking. In this Letter, we propose to support the distinction between two-dimensional conventional 𝑠-wave and topological 𝑝-wave superconductors by above-gap transport signatures. Our method utilizes the emergence of Tomasch oscillations of quasiparticles in a junction consisting of a superconductor sandwiched between two metallic leads. We demonstrate that the behavior of the oscillations in conductance as a function of the interface barriers provides a distinctive signature for 𝑠-wave and 𝑝-wave superconductors. Specifically, the oscillations become weaker as the barrier strength increases in 𝑠-wave superconductors, while they become more pronounced in 𝑝-wave superconductors, which we prove to be a direct manifestation of the pairing symmetries. Our method can serve as a complimentary probe for identifying some classes of topological superconductors through the above-gap transport.

• Keywords (english): Tomasch Oscillations; Topological Superconductivity
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review Letters
• Numbering: vol. 132, no. 6, 066301
• p-ISSN: 0031-9007
• e-ISSN: 1079-7114
• DOI: https://doi.org/10.1103/PhysRevLett.132.066301
• URN:NBN: urn:nbn:hr:217:344520
• Publication: 2024
• Document URL: https://link.aps.org/doi/10.1103/PhysRevLett.132.066301
• Type of resource: Text
• Access conditions: Open access
• Public note: Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Received 16 May 2023; revised 3 October 2023; accepted 8 January 2024; published 7 February 2024.
• Created on: 2024-07-31 08:47:55