Journal article Anisotropic transport of Josephson vortices in atomic-layer superconductors on vicinal surfaces
Wenxuan Qian (author) (Search by this author)
;
Yash Chauhan (author) (Search by this author)
ORCID https://orcid.org/0009-0000-9371-2813 (unauthenticated)
ORCID ; ORCID SAMURAI ; ORCID SAMURAI ; ORCID SAMURAI ; ORCID SAMURAI
ms_v2.pdf
Download file (1.14 MB)
Download as zip (1.12 MB)
Collection

Citation
Wenxuan Qian, Yash Chauhan, Ryohei Nemoto, Keisuke Sagisaka, Shunsuke Yoshizawa, Takashi Uchihashi. Anisotropic transport of Josephson vortices in atomic-layer superconductors on vicinal surfaces. Physical Review B. 2026, 114 (5), 055422. https://doi.org/10.1103/b2j3-xj19

Description:

(abstract)

Atomic steps have strong influences on surface two-dimensional superconductors. Josephson vortices formed at the atomic steps under magnetic fields may dominate transport phenomena at low temperatures, but its experimental verification is still lacking. Here, we report the vortex transport properties of atomic-layer superconductor Si(111)-(root7xroot3)-In with vicinal surfaces, for which Josephson vortices are directly observed by scanning tunneling microscopy. A sharp drop in resistance with decreasing temperature T, detected under out-of-plane magnetic field B, reveals a distinctive anisotropy with respect to the atomic step direction. The anisotropy of sheet resistance, proportional to that of vortex mobility, amounts to the order of 10^3 at intermediate magnetic fields. In the high-T and low-B region, Josephson vortices exhibit thermally excited creep motions with anisotropic activation energy U_act. A further increase in B suppresses U_act toward zero anisotropically, resulting in one-dimensional pinning-free vortex flow at 0.10 < B < 0.20 T. At the lowest temperatures, the vortex motion is governed by quantum tunneling. A B-T phase diagram constructed based on these measurements reveals multiple regions characterized by directionally dependent vortex-transport mechanisms.

Rights:

Keyword: superconductivity, surface, atomic step, Josephson vortex, transport, anisotropy

Date published: 2026-07-30

Publisher: American Physical Society (APS)

Journal:

  • Physical Review B (ISSN: 24699950) vol. 114 issue. 5 055422

Funding:

  • Japan Society for the Promotion of Science 25H00867
  • Japan Society for the Promotion of Science 24K01351
  • Japan Society for the Promotion of Science 22H01961
  • Japan Society for the Promotion of Science 25K01670
  • Ministry of Education, Culture, Sports, Science and Technology

Manuscript type: Author's version (Accepted manuscript)

MDR DOI: https://doi.org/10.48505/nims.6434

First published URL: https://doi.org/10.1103/b2j3-xj19

Related item:

Other identifier(s):

Contact agent:

Updated at: 2026-08-03 09:07:51 +0900

Published on MDR: 2026-08-03 10:28:56 +0900

Filename Size
Filename ms_v2.pdf (Thumbnail)
application/pdf 		Size 1.14 MB Detail