# In heterojunction problem, how to align the energy band in presence of bias voltage

For example, SiO$_2$ barrier embeded between Fe magnet and 2-dimensional-electron-gas such as Si.

How to align the energy bands of the three materials when an electric field is perpendicular to the interfaces?

Do they have the same Fermi level? Could somebody draw the band offset for me? Where can I find the data of band offset?

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