مؤتمر
Causality, 'superluminality', and reshaping in undersized waveguides
| العنوان: | Causality, 'superluminality', and reshaping in undersized waveguides |
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| المؤلفون: | Sokolovski, D., Akhmatskaya, E. |
| سنة النشر: | 2012 |
| المجموعة: | BIRD - BCAM's Institutional Repository Data (Basque Center for Applied Mathematics) |
| مصطلحات موضوعية: | Apparent 'superluminality', The Hartman effect, Wave propagation |
| الوصف: | We analyse the reshaping mechanism leading to apparently 'superluminal' advancement of a pulse traversing an undersized section of a waveguide. For frequencies below the first inelastic threshold (cut off one), there are only evanescent modes in the narrow region, and the problem becomes similar to quantum mechanical tunnelling across an effective rectangular 'barrier'. In the coordinate representation, the barrier is shown to act as an effective beamsplitter, recombining envelopes of the freely propagating pulse with various spacial shifts. Causality ensures that none of the constituent envelopes are advanced with respect to free propagation, yet the resulting pulse is advanced due to a peculiar interference effect, similar to the one responsible for 'anomalous' values which occur in Aharonov's 'weak measurements'. In the momentum space, the effect is understood as a bandwidth phenomenon, where the incident pulse probes local, rather than global, analytical properties of the transmission amplitude T(p). The advancement is achieved when T(p) mimics locally an exponential behaviour, similar to the one occurring in Berry's 'superoscillations'. |
| نوع الوثيقة: | conference object |
| وصف الملف: | application/pdf |
| اللغة: | English |
| ردمك: | 978-3-9503537-0-9 3-9503537-0-4 |
| العلاقة: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84871638254&partnerID=40&md5=0827cadce20e9df5aed6471135d96074Test; http://hdl.handle.net/20.500.11824/425Test |
| الإتاحة: | https://doi.org/20.500.11824/425Test https://hdl.handle.net/20.500.11824/425Test |
| حقوق: | Reconocimiento-NoComercial-CompartirIgual 3.0 España ; http://creativecommons.org/licenses/by-nc-sa/3.0/esTest/ ; info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.2DA38CE2 |
| قاعدة البيانات: | BASE |
| ردمك: | 9783950353709 3950353704 |
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