Localization-delocalization wavepacket transition in Pythagorean aperiodic potentials
We introduce a composite optical lattice created by two mutually rotated square patterns and allowing observation of continuous transformation between incommensurate and completely periodic structures upon variation of the rotation angle ¿. Such lattices acquire periodicity only for rotation angles...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/98445 |
| Acceso en línea: | https://hdl.handle.net/2117/98445 https://dx.doi.org/10.1038/srep32546 |
| Access Level: | acceso abierto |
| Palabra clave: | Optical communications Optical materials and structures Optical physics Comunicacions òptiques Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica |
| Sumario: | We introduce a composite optical lattice created by two mutually rotated square patterns and allowing observation of continuous transformation between incommensurate and completely periodic structures upon variation of the rotation angle ¿. Such lattices acquire periodicity only for rotation angles cos¿¿¿=¿a/c, sin¿¿¿=¿b/c, set by Pythagorean triples of natural numbers (a, b, c). While linear eigenmodes supported by lattices associated with Pythagorean triples are always extended, composite patterns generated for intermediate rotation angles allow observation of the localization-delocalization transition of eigenmodes upon modification of the relative strength of two sublattices forming the composite pattern. Sharp delocalization of supported modes for certain ¿ values can be used for visualization of Pythagorean triples. The effects predicted here are general and also take place in composite structures generated by two rotated hexagonal lattices. |
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