deletions | additions       diff --git a/We_can_calculate_its_dispersion__.tex b/We_can_calculate_its_dispersion__.tex  index 75bf6e8..e8de62a 100644  --- a/We_can_calculate_its_dispersion__.tex  +++ b/We_can_calculate_its_dispersion__.tex 
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We can calculate its dispersion relation and get Fig.5. Only when v=w, the dispersion exhibits like a conductor.