# Schrodinger Equations - wave propagation

krindik
Hi,
Can somebody point me in the correct direction of learning about Schrodinger Equations in relation to Wave propagation. I came across Schrodinger Equations in some texts but couldn't quite understand some background. Most of the time the author used it from nowhere.

Really appreciate if you would point me to some online / book references.
Even wikipedia gives only a set of equations. I would hope some derivation/formulation based on Maxwell equations.

Thanks

Peeter
What background do you have? If you are comfortable with Fourier transforms the Dover book Quantum Theory by David Bohm does a nice job motivating this.

Note that Schrodenger's equation is not derived from Maxwell's equations.

krindik
Thanks.
Yes I'm OK with Fourier transforms.
I'm looking to understand the Schrodinger relationship in the context of wave propagation.

http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/schrcn.html
speaks only in abstract terms.

So far I'm happily going through understanding dispersion, dielectric loss etc. But in several references I came across the Shrodinger equation but don't know how it fits in with wave propagation.

naturale
Take the wave equation and you see that the solution can be written as
φ(x,t) = A(x) e^{- i t w} where omega is the angular frequency. De Broglie says that the energy is E = \hbar w . Now you see that the Schrodinger equation id the square root of the wave equation.

i \hbar ∂ φ(x, t) / ∂ t = E φ(x, t)

sokrates
De Broglie says that the energy is E = \hbar w

Einstein says that.

krindik
Thanks naturale !
That was very clear.
Anyway why is the wave equation represented as a schrodinger equation? Is there any particular importance related to wave propagation.

I would really like to read some text with explanation like u gave + plus some insights into the importance of representing in schrodinger equation. Could u point me to some?

Thanks

naturale
In the relativistic limit the Schrodinger equation becomes the KG equation, which (in particular in the massless case) represents a wave with velocity c. If you want to see the relation of the SE with wave equation you must study quantum field theory.

To have an idea look to http://en.wikipedia.org/wiki/Klein-Gordon_equation .

I don't how much in details you want to go, but on the interpretation of QM in terms of classical periodic waves my filling is that it is starting a new era.