Normal electric field across the interface

AI Thread Summary
The discussion centers on the behavior of the normal electric field at the interface between two dielectric materials with differing dielectric functions. It highlights that while traditional boundary conditions suggest a discontinuity in the electric field, real-world scenarios involve a gradual variation over a finite spatial region, typically on the atomic scale. This gradual change is often negligible in macroscopic electromagnetic theory. The conversation also clarifies that the variation of material properties with space is distinct from boundary conditions. Literature on the true variation of the normal electric field across interfaces is sought for further understanding.
Jeffrey Yang
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Dear all:

The boundary condition of electric field is well know for us which illustrates that the normal component of the electric field will not be continuous across the interface between 2 dielectric material with different dielectric functions. (There is no extra fixed charge on the interface in my consideration).

However, in the real word, there would be no really abrupt change of physical values. The variation of the normal field should happen in a finite spatial region, typically should be on the scale of several layers of atom and can be well ignored in macroscopic EM theory. This is what I thought.

Is this correct? Dose anyone have literature on the "true variation of normal electric field across interface"?

Thanks very much
 
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What you want, by definition, is not called boundary conditions. You're talking about variation of the properties of a material with space. Which is accommodated in physics by relaxing the condition that the properties of a material are constant and so they're regarded as functions of spatial coordinates and time for that material.
Of course when you stick two different materials together, there is an abrupt change in the properties at the boundary.
 
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