Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state
Abstract Under the influence of a constant drive the moving vortex state in 2H-NbS2 superconductor exhibits a negative differential resistance (NDR) transition from a steady flow to an immobile state. This state possesses a high depinning current threshold ( $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{...
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| Format: | Article |
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Nature Portfolio
2017-07-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-017-05191-6 |
| _version_ | 1818405766238830592 |
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| author | Biplab Bag Gorky Shaw S. S. Banerjee Sayantan Majumdar A. K. Sood A. K. Grover |
| author_facet | Biplab Bag Gorky Shaw S. S. Banerjee Sayantan Majumdar A. K. Sood A. K. Grover |
| author_sort | Biplab Bag |
| collection | DOAJ |
| description | Abstract Under the influence of a constant drive the moving vortex state in 2H-NbS2 superconductor exhibits a negative differential resistance (NDR) transition from a steady flow to an immobile state. This state possesses a high depinning current threshold ( $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h ) with unconventional depinning characteristics. At currents well above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h , the moving vortex state exhibits a multimodal velocity distribution which is characteristic of vortex flow instabilities in the NDR regime. However at lower currents which are just above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h , the velocity distribution is non-Gaussian with a tail extending to significant negative velocity values. These unusual negative velocity events correspond to vortices drifting opposite to the driving force direction. We show that this distribution obeys the Gallavotti-Cohen Non-Equilibrium Fluctuation Relation (GC-NEFR). Just above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h , we also find a high vortex density fluctuating driven state not obeying the conventional GC-NEFR. The GC-NEFR analysis provides a measure of an effective energy scale (E eff ) associated with the driven vortex state. The E eff corresponds to the average energy dissipated by the fluctuating vortex state above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h . We propose the high E eff value corresponds to the onset of high energy dynamic instabilities in this driven vortex state just above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h . |
| first_indexed | 2024-12-14T09:01:16Z |
| format | Article |
| id | doaj.art-9d8a9bf7ea624bb3bd729d232e70997e |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-14T09:01:16Z |
| publishDate | 2017-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-9d8a9bf7ea624bb3bd729d232e70997e2022-12-21T23:08:48ZengNature PortfolioScientific Reports2045-23222017-07-01711910.1038/s41598-017-05191-6Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex stateBiplab Bag0Gorky Shaw1S. S. Banerjee2Sayantan Majumdar3A. K. Sood4A. K. Grover5Department of Physics, Indian Institute of TechnologyDepartment of Physics, Indian Institute of TechnologyDepartment of Physics, Indian Institute of TechnologyDepartment of Physics, Indian Institute of ScienceDepartment of Physics, Indian Institute of ScienceDepartment of Physics, Panjab UniversityAbstract Under the influence of a constant drive the moving vortex state in 2H-NbS2 superconductor exhibits a negative differential resistance (NDR) transition from a steady flow to an immobile state. This state possesses a high depinning current threshold ( $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h ) with unconventional depinning characteristics. At currents well above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h , the moving vortex state exhibits a multimodal velocity distribution which is characteristic of vortex flow instabilities in the NDR regime. However at lower currents which are just above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h , the velocity distribution is non-Gaussian with a tail extending to significant negative velocity values. These unusual negative velocity events correspond to vortices drifting opposite to the driving force direction. We show that this distribution obeys the Gallavotti-Cohen Non-Equilibrium Fluctuation Relation (GC-NEFR). Just above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h , we also find a high vortex density fluctuating driven state not obeying the conventional GC-NEFR. The GC-NEFR analysis provides a measure of an effective energy scale (E eff ) associated with the driven vortex state. The E eff corresponds to the average energy dissipated by the fluctuating vortex state above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h . We propose the high E eff value corresponds to the onset of high energy dynamic instabilities in this driven vortex state just above $${{\boldsymbol{I}}}_{{\boldsymbol{c}}}^{{\boldsymbol{h}}}$$ I c h .https://doi.org/10.1038/s41598-017-05191-6 |
| spellingShingle | Biplab Bag Gorky Shaw S. S. Banerjee Sayantan Majumdar A. K. Sood A. K. Grover Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state Scientific Reports |
| title | Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state |
| title_full | Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state |
| title_fullStr | Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state |
| title_full_unstemmed | Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state |
| title_short | Negative velocity fluctuations and non-equilibrium fluctuation relation for a driven high critical current vortex state |
| title_sort | negative velocity fluctuations and non equilibrium fluctuation relation for a driven high critical current vortex state |
| url | https://doi.org/10.1038/s41598-017-05191-6 |
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