WAVELET METHOD FOR CALCULATING THE DEFECT STATES OF TWO-DIMENSIONAL PHONONIC CRYSTALS

(整期优先)网络出版时间:2008-02-12
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Basedonthevariationaltheory,awavelet-basednumericalmethodisdevelopedtocalculatethedefectstatesofacousticwavesintwo-dimensionalphononiccrystalswithpointandlinedefects.Thesupercelltechniqueisapplied.Byexpandingthedisplacementfieldandthematerialconstants(massdensityandelasticstiffness)inperiodicwavelets,theexplicitformula-tionsofaneigenvalueproblemfortheplaneharmonicbulkwavesinsuchaphononicstructurearederived.Thepointandlinedefectstatesinsolid-liquidandsolid-solidsystemsarecalcu-lated.Comparisonsofthepresentresultswiththosemeasuredexperimentallyorthosefromtheplanewaveexpansionmethodshowthatthepresentmethodcanyieldaccurateresultswithfasterconvergenceandlesscomputingtime.