[Q]How can i draw real graph from complex function?

In summary, the conversation is about a simple eigen function that cannot be drawn on a real coordinate due to its complex form. The question is how to draw this function and how to determine the amplitude of the transmission wave from the transmission coefficient in a potential barrier problem. The expression for the transmission coefficient contains an absolute value which may not accurately represent the real transmission amplitude. The conversation also discusses matching inner and outer solutions for the wavefunction to be continuous, and suggests plotting a 3D graph to visualize the complex function.
  • #1
good_phy
45
0
For instance,

I have a simple eigen function such as [itex] \varphi = Ae^{ik_{1}x} + Be^{-ik_{1}x} [/itex]

This is complex form which means we can't draw this function on real coordinate.

How can i draw this function? just By taking out real term of complex function?


Second question is what does transmission coefficient means. What exactly i want to know

is how to know amplitude of transmission wave from transmission coefficient in potential

barrier problem? For instance, in problem such that x < a, v = 0 and x >= a, v = c,

Transmission coefficient [itex] T = |\frac{C}{A}|^2\frac{k_2}{k_1} [/itex]

But This expression contains absolute value of ratio A to C, So I'm not sure that This

expression indicate real transmission amplitute C when we know Incident amplitute A.

More over, I'm confusion that whether amplitute of wave can be complex number.
 
Physics news on Phys.org
  • #2
You know that you can write that function in terms of cos and sine right? i.e that wavefunction is a sinosodial one with one term propagating to the right and one propagating to the left.

You must match the inner solution with the outer solution so that the wavefuntion is continuous and has continuous derivative at the boundary. Very standard exercise in intro QM.
 
  • #3
In addition, you could plot 3D graph as follows: let the x coordinate be the real part of the input, let the y coordinate be the complex part of the input, and let z be the magnitude of the output. You can change this around to get the complex part of the output, etc.
 

1. What is a complex function?

A complex function is a mathematical function that takes in a complex number as its input and outputs another complex number. It can be written in the form f(z) = u(x,y) + iv(x,y), where z = x + iy, u and v are real-valued functions, and i is the imaginary unit.

2. Can complex functions be graphed?

Yes, complex functions can be graphed, but the resulting graph will have two dimensions (real and imaginary) instead of the traditional one-dimensional graph for real functions.

3. How do I draw a real graph from a complex function?

To draw a real graph from a complex function, you can plot the real parts of the output complex numbers on the x-axis and the imaginary parts on the y-axis. This will give you a two-dimensional representation of the complex function.

4. What is the purpose of graphing complex functions?

Graphing complex functions can help visualize the behavior and properties of the function. It can also aid in understanding the relationship between the input and output complex numbers.

5. Are there any tools or software that can help me graph complex functions?

Yes, there are many tools and software available that can help you graph complex functions. Some popular options include Wolfram Alpha, Desmos, and GeoGebra. These tools often have features specifically designed for graphing complex functions.

Similar threads

  • Advanced Physics Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
17
Views
1K
  • Advanced Physics Homework Help
Replies
2
Views
2K
Replies
5
Views
1K
  • Advanced Physics Homework Help
Replies
1
Views
986
  • Differential Equations
Replies
3
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
1K
Replies
1
Views
544
  • Advanced Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
552
Back
Top