Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction

Superconductors exhibit dissipationless supercurrents even under finite bias and magnetic field conditions, provided these remain below the critical values. However, type-II superconductors in the flux flow regime display Ohmic dissipation arising from vortex dynamics under finite magnetic fields. T...

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Main Authors: Minseong Kwon, Mingi Kim, Yoonji Gong, Heeyeon Lee, Young Duck Kim
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:Materials for Quantum Technology
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Online Access:https://doi.org/10.1088/2633-4356/adae49
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author Minseong Kwon
Mingi Kim
Yoonji Gong
Heeyeon Lee
Young Duck Kim
author_facet Minseong Kwon
Mingi Kim
Yoonji Gong
Heeyeon Lee
Young Duck Kim
author_sort Minseong Kwon
collection DOAJ
description Superconductors exhibit dissipationless supercurrents even under finite bias and magnetic field conditions, provided these remain below the critical values. However, type-II superconductors in the flux flow regime display Ohmic dissipation arising from vortex dynamics under finite magnetic fields. The interplay between supercurrent and Ohmic dissipation in a type-II superconductor is dictated by vortex motion and the robustness of vortex pinning forces. In this study, we present an experimental investigation of the superconducting phase transitions and vortex dynamics in the atomically thin type-II superconductor 2H-NbSe _2 . We fabricated a high-quality multilayer 2H-NbSe _2 with a step junction, demonstrating supercurrent in clean limit below a critical temperature of 6.6 K and a high residual resistance ratio of 17. The upper critical field was estimated to be 4.5 T and the Ginzburg–Landau coherence length 8.6 nm. Additionally, we observed phase transitions induced by vortex viscous dynamics in the 2H-NbSe _2 step junction. Analysis of the pinning force density using the Dew-Hughes model indicates that the pinning force in the 2H-NbSe _2 device can be attributed to step junction, related to the surface-Δ κ type of pinning centers. Our findings pave the way for engineering pinning forces by introducing artificial pinning centers through partial atomic thickness variation in layered 2D superconductors while minimizing unwanted quality degradation in the system.
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spelling doaj-art-4a2df6a229234e69a1109e61228af66a2025-02-06T16:50:19ZengIOP PublishingMaterials for Quantum Technology2633-43562025-01-015101520110.1088/2633-4356/adae49Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junctionMinseong Kwon0https://orcid.org/0009-0006-9804-4213Mingi Kim1https://orcid.org/0000-0002-1146-6186Yoonji Gong2https://orcid.org/0009-0003-6377-8856Heeyeon Lee3https://orcid.org/0009-0005-8497-6434Young Duck Kim4https://orcid.org/0000-0003-2593-9826Department of Physics, Kyung Hee University , Seoul 02447, Republic of KoreaDepartment of Physics, Kyung Hee University , Seoul 02447, Republic of KoreaKHU-KIST Department of Converging Science and Technology, Kyung Hee University , Seoul 02447, Republic of KoreaDepartment of Physics, Kyung Hee University , Seoul 02447, Republic of KoreaDepartment of Physics, Kyung Hee University , Seoul 02447, Republic of Korea; KHU-KIST Department of Converging Science and Technology, Kyung Hee University , Seoul 02447, Republic of Korea; Department of Information Display, Kyung Hee University , Seoul 02447, Republic of KoreaSuperconductors exhibit dissipationless supercurrents even under finite bias and magnetic field conditions, provided these remain below the critical values. However, type-II superconductors in the flux flow regime display Ohmic dissipation arising from vortex dynamics under finite magnetic fields. The interplay between supercurrent and Ohmic dissipation in a type-II superconductor is dictated by vortex motion and the robustness of vortex pinning forces. In this study, we present an experimental investigation of the superconducting phase transitions and vortex dynamics in the atomically thin type-II superconductor 2H-NbSe _2 . We fabricated a high-quality multilayer 2H-NbSe _2 with a step junction, demonstrating supercurrent in clean limit below a critical temperature of 6.6 K and a high residual resistance ratio of 17. The upper critical field was estimated to be 4.5 T and the Ginzburg–Landau coherence length 8.6 nm. Additionally, we observed phase transitions induced by vortex viscous dynamics in the 2H-NbSe _2 step junction. Analysis of the pinning force density using the Dew-Hughes model indicates that the pinning force in the 2H-NbSe _2 device can be attributed to step junction, related to the surface-Δ κ type of pinning centers. Our findings pave the way for engineering pinning forces by introducing artificial pinning centers through partial atomic thickness variation in layered 2D superconductors while minimizing unwanted quality degradation in the system.https://doi.org/10.1088/2633-4356/adae492H-NbSe22D superconductorsuperconductivityflux pinningflux flow phasenano-step junction
spellingShingle Minseong Kwon
Mingi Kim
Yoonji Gong
Heeyeon Lee
Young Duck Kim
Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction
Materials for Quantum Technology
2H-NbSe2
2D superconductor
superconductivity
flux pinning
flux flow phase
nano-step junction
title Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction
title_full Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction
title_fullStr Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction
title_full_unstemmed Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction
title_short Flux pinning in superconducting multilayer 2H-NbSe2 nano-step junction
title_sort flux pinning in superconducting multilayer 2h nbse2 nano step junction
topic 2H-NbSe2
2D superconductor
superconductivity
flux pinning
flux flow phase
nano-step junction
url https://doi.org/10.1088/2633-4356/adae49
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AT yoonjigong fluxpinninginsuperconductingmultilayer2hnbse2nanostepjunction
AT heeyeonlee fluxpinninginsuperconductingmultilayer2hnbse2nanostepjunction
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