Version 1
: Received: 31 May 2022 / Approved: 31 May 2022 / Online: 31 May 2022 (06:17:46 CEST)
Version 2
: Received: 27 June 2022 / Approved: 28 June 2022 / Online: 28 June 2022 (03:48:23 CEST)
Version 3
: Received: 8 September 2022 / Approved: 9 September 2022 / Online: 9 September 2022 (04:01:57 CEST)
Version 4
: Received: 15 September 2023 / Approved: 15 September 2023 / Online: 18 September 2023 (03:19:17 CEST)
How to cite:
Zen, N. Sayonara BCS: Realization of Room Temperature Superconductivity as a result of a First Order Phase Transition. Preprints2022, 2022050411. https://doi.org/10.20944/preprints202205.0411.v4
Zen, N. Sayonara BCS: Realization of Room Temperature Superconductivity as a result of a First Order Phase Transition. Preprints 2022, 2022050411. https://doi.org/10.20944/preprints202205.0411.v4
Zen, N. Sayonara BCS: Realization of Room Temperature Superconductivity as a result of a First Order Phase Transition. Preprints2022, 2022050411. https://doi.org/10.20944/preprints202205.0411.v4
APA Style
Zen, N. (2023). Sayonara BCS: Realization of Room Temperature Superconductivity as a result of a First Order Phase Transition. Preprints. https://doi.org/10.20944/preprints202205.0411.v4
Chicago/Turabian Style
Zen, N. 2023 "Sayonara BCS: Realization of Room Temperature Superconductivity as a result of a First Order Phase Transition" Preprints. https://doi.org/10.20944/preprints202205.0411.v4
Abstract
By making periodic thru-holes in a suspended film, the phonon system can be modified. Motivated by the BCS theory, the technique -- so-called phonon engineering -- was applied to a metallic niobium sheet. It was found that its electrical resistance dropped to zero at 175 K, and the zero-resistance state persisted up to 290 K in the subsequent warming process. Despite the initial motivation, neither these high transition temperatures nor the phase transition with thermal hysteresis can be accounted for by the BCS theory. Therefore, we abandon the BCS theory. Instead, it turns out that the metallic holey sheet is partly oxidized to form a niobium-oxygen square lattice, which has points of resemblance to a copper-oxygen plane, the fundamental component of cuprate high-Tc superconductors. Therefore, the pairing mechanism underlying this study should be related to that of cuprate high-Tc superconductors, which we may not yet understand. In addition to the electrical results of zero resistance, the holey sheet exhibited a decrease in magnetization upon cooling, i.e., the Meissner effect. Moreover, the remnant magnetization was clearly detected at 300 K, which can only be attributed to persistent currents flowing in a superconducting sample. Thus, this study meets the established criteria for a conclusive demonstration of true superconductivity. Finally, the superconducting transition with the unambiguous thermal hysteresis is discussed. According to Halperin, Lubensky, and Ma, or HLM for short, any superconducting transition must always be first order with thermal hysteresis because of the intrinsic fluctuating magnetic field. The HLM theory is very compatible with the highly oriented system harboring two-dimensional superconductivity.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received:
18 September 2023
Commenter:
Nobuyuki Zen
Commenter's Conflict of Interests:
Author
Comment:
The anomalously wide thermal hysteresis (Fig. 4) can be explained by the Halperin-Lubensky-Ma theory, see pages 10-11. Also, the title and conclusion section are updated to prevent misunderstandings.
Commenter: Nobuyuki Zen
Commenter's Conflict of Interests: Author