- #1
IcedCoffee
- 21
- 4
I've been having a sign problem while deriving the permittivity formula using Drude model,
and I found out that the problem came from the fact that complex field vectors are expressed with e-iwt, not eiwt, thus producing (-iwt) term when differentiated:
http://photonics101.com/light-matter-interactions/drude-model-metal-permittivity-conductivity (See "Show Solutions")
Now, I guess that when you pick either eiwt or e-iwt and derive complex parameters like permittivity, you have to stick with it from then on in order to obtain valid real-part values with correct phase,
but is e-iwt the conventional one? I've seen the same formula for permittivity in Wikipedia... Is this because i(kx-wt) is more natural for waves propagating to positive x direction?
and I found out that the problem came from the fact that complex field vectors are expressed with e-iwt, not eiwt, thus producing (-iwt) term when differentiated:
http://photonics101.com/light-matter-interactions/drude-model-metal-permittivity-conductivity (See "Show Solutions")
Now, I guess that when you pick either eiwt or e-iwt and derive complex parameters like permittivity, you have to stick with it from then on in order to obtain valid real-part values with correct phase,
but is e-iwt the conventional one? I've seen the same formula for permittivity in Wikipedia... Is this because i(kx-wt) is more natural for waves propagating to positive x direction?