Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Complex permeability and permittivity

  1. Apr 4, 2012 #1
    Hello All,

    I have a question regarding complex permeability and permittivity, in particular, regarding their use with the complex refractive index in Mie theory.

    If the material is not dielectric, the permeability/permittivity needs to be accounted for while calculating the scattering coefficients. I have the material properties (complex refractive index and complex dielectric function) at the given wavelength. Yet, I do not have the complex permittivity or permeability. I know you can use LLG equation and derive the complex permeability, but I was wondering if there was an alternative way.

    Or let's say that since I do have this complex refractive index, can I simply ignore the relative permeability in the scattering coefficients? My logic says no since some materials could have a permeability of several thousand or more. I checked Kittel, Jackson, and even my trusted source in anything related to physics, Landau's books. Unless I missed something, I could not find something helpful.

    Can someone start me along the right path perhaps??

    Thanks in advance!
     
  2. jcsd
  3. Apr 5, 2012 #2

    DrDu

    User Avatar
    Science Advisor

    How can a material not be dielectric but have a permittivity?

    At optical frequencies, permeability is encoded in the wavenumber dependence of the dielectric tensor. In lowest order, this is taken care off by the distinction between longitudinal and transversal dielectric constant. I wonder that you did not find anything in Landau, as he discusses it at length in "Electrodynamics of continua".
     
  4. Apr 9, 2012 #3
    DrDu,

    Thank you for your reply. Upon your instructions, I actually revisited Electrodynamics of Continua and found what I was looking for. Additionally, I went ahead and did a numerical/asymptotic solutions for the LLG equations and found the value of the permeability I needed.

    Thanks again for your help!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook