Semifluxons in long Josephson junctions with phase shifts
A Josephson junction is formed by sandwiching a non-superconducting material between two superconductors. If the phase difference across the superconductors is zero, the junction is called a conventional junction, otherwise it is unconventional junction. Unconventional Josephson junctions are widely...
| Main Author: | |
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
| Published: |
2012
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| Online Access: | https://eprints.nottingham.ac.uk/12729/ |
| _version_ | 1848791569023369216 |
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| author | Ahmad, Saeed |
| author_facet | Ahmad, Saeed |
| author_sort | Ahmad, Saeed |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | A Josephson junction is formed by sandwiching a non-superconducting material between two superconductors. If the phase difference across the superconductors is zero, the junction is called a conventional junction, otherwise it is unconventional junction. Unconventional Josephson junctions are widely used in information process and storage.
First we investigate long Josephson junctions having two p-discontinuity points characterized by a shift of p in phase, that is, a 0-p-0 long Josephson junction, on both infinite and finite domains. The system is described by a modified sine-Gordon equation with an additional shift q(x) in the nonlinearity. Using a perturbation technique, we investigate an instability region where semifluxons are spontaneously generated. We study the dependence of semifluxons on the facet length, and the applied bias current.
We then consider a disk-shaped two-dimensional Josephson junction with concentric regions of 0- and p-phase shifts and investigate the ground state of the system both in finite and infinite domain. This system is described by a (2 + 1) |
| first_indexed | 2025-11-14T18:30:35Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-12729 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T18:30:35Z |
| publishDate | 2012 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-127292025-02-28T11:21:02Z https://eprints.nottingham.ac.uk/12729/ Semifluxons in long Josephson junctions with phase shifts Ahmad, Saeed A Josephson junction is formed by sandwiching a non-superconducting material between two superconductors. If the phase difference across the superconductors is zero, the junction is called a conventional junction, otherwise it is unconventional junction. Unconventional Josephson junctions are widely used in information process and storage. First we investigate long Josephson junctions having two p-discontinuity points characterized by a shift of p in phase, that is, a 0-p-0 long Josephson junction, on both infinite and finite domains. The system is described by a modified sine-Gordon equation with an additional shift q(x) in the nonlinearity. Using a perturbation technique, we investigate an instability region where semifluxons are spontaneously generated. We study the dependence of semifluxons on the facet length, and the applied bias current. We then consider a disk-shaped two-dimensional Josephson junction with concentric regions of 0- and p-phase shifts and investigate the ground state of the system both in finite and infinite domain. This system is described by a (2 + 1) 2012-07-19 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/12729/1/Saeed_PhD_Thesis.pdf Ahmad, Saeed (2012) Semifluxons in long Josephson junctions with phase shifts. PhD thesis, University of Nottingham. |
| spellingShingle | Ahmad, Saeed Semifluxons in long Josephson junctions with phase shifts |
| title | Semifluxons in long Josephson junctions with phase shifts |
| title_full | Semifluxons in long Josephson junctions with phase shifts |
| title_fullStr | Semifluxons in long Josephson junctions with phase shifts |
| title_full_unstemmed | Semifluxons in long Josephson junctions with phase shifts |
| title_short | Semifluxons in long Josephson junctions with phase shifts |
| title_sort | semifluxons in long josephson junctions with phase shifts |
| url | https://eprints.nottingham.ac.uk/12729/ |