Depairing critical current density and the vortex-free state in FeSe nanobridges

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sun, Yue, Xiang, Yuling, Shi, Zhixiang, Tamegai, Tsuyoshi
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912726671949824
author Sun, Yue
Xiang, Yuling
Shi, Zhixiang
Tamegai, Tsuyoshi
author_facet Sun, Yue
Xiang, Yuling
Shi, Zhixiang
Tamegai, Tsuyoshi
contents The depairing limit and the vortex-free state in a superconductor is crucial for both the study of supercurrent related physics and the application eliminating noise linked to vortex motion. In this work, we report the evidence of depairing limit and the vortex-free state achieved by geometric constraint in FeSe superconductors. A series of narrow bridges with varying widths at the same location of a single crystal were prepared by the \textquotedblleft pickup\textquotedblright method using successive focused ion beam millings. By simply reducing the width of bridge, the magnitude of critical current density ($J_{\rm{c}}$) is enhanced more than one order, evidence the achievement of depairing limit. Moreover, in the bridge with a width smaller than the penetration depth ($λ$), $J_{\rm{c}}$ is found to be robust against magnetic field up to 1 kOe. The field-robust $J_{\rm{c}}$ is a strong piece of evidence for vortex-free state, which is created by the enhancement of lower critical fields due to geometric constraint.
format Preprint
id arxiv_https___arxiv_org_abs_2511_19054
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Depairing critical current density and the vortex-free state in FeSe nanobridges
Sun, Yue
Xiang, Yuling
Shi, Zhixiang
Tamegai, Tsuyoshi
Superconductivity
Strongly Correlated Electrons
The depairing limit and the vortex-free state in a superconductor is crucial for both the study of supercurrent related physics and the application eliminating noise linked to vortex motion. In this work, we report the evidence of depairing limit and the vortex-free state achieved by geometric constraint in FeSe superconductors. A series of narrow bridges with varying widths at the same location of a single crystal were prepared by the \textquotedblleft pickup\textquotedblright method using successive focused ion beam millings. By simply reducing the width of bridge, the magnitude of critical current density ($J_{\rm{c}}$) is enhanced more than one order, evidence the achievement of depairing limit. Moreover, in the bridge with a width smaller than the penetration depth ($λ$), $J_{\rm{c}}$ is found to be robust against magnetic field up to 1 kOe. The field-robust $J_{\rm{c}}$ is a strong piece of evidence for vortex-free state, which is created by the enhancement of lower critical fields due to geometric constraint.
title Depairing critical current density and the vortex-free state in FeSe nanobridges
topic Superconductivity
Strongly Correlated Electrons
url https://arxiv.org/abs/2511.19054