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PDE, Dirac equation with magnetic field, wrong solution at zero

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Hi,

I’m using the coefficient form PDE to solve the Dirac equation for massless electrons (graphene) in a magnetic field. It’s a very simple 1D axisymmetric model.

The expected solutions are discrete Landau levels. The Comsol model does give me those results, for the most part, but there are some issues. There should be a single eigenvalue at zero, but the model solution gives two - one very small positive value and one very small negative value.
Furthermore, there are similar extra (wrong) solutions at every fifth level above and below zero. Instead of the expected single eigenvalue, there are two very close values.

Any idea what could be going wrong here?


0 Replies Last Post 27 sept. 2013, 09:11 UTC−4
COMSOL Moderator

Hello Dean Moldovan

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