Quantum mechanics - finite square well

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SUMMARY

The discussion focuses on the relationship between transmission (T), reflection (R), and the wave number (k) in the context of a finite square well in quantum mechanics. Participants clarify that T is maximized when the potential width (V_0) is minimized, leading to full transmission when V_0 is infinitely wide. The formulas for T and R are defined as T = 1 - R and R = |A|²/|B|², with k defined as k = √(2m(V_0 - E)/ħ). Understanding these relationships is crucial for analyzing particle behavior in quantum wells.

PREREQUISITES
  • Understanding of quantum mechanics principles, specifically wave-particle duality.
  • Familiarity with the finite square well model in quantum mechanics.
  • Knowledge of the Schrödinger equation and wave functions.
  • Basic grasp of mathematical concepts such as square roots and complex numbers.
NEXT STEPS
  • Study the derivation of the finite square well potential in quantum mechanics.
  • Learn about the implications of varying potential widths on transmission and reflection coefficients.
  • Explore the relationship between energy levels and wave functions in quantum systems.
  • Investigate the role of boundary conditions in determining wave behavior in quantum mechanics.
USEFUL FOR

Students and professionals in physics, particularly those specializing in quantum mechanics, as well as educators seeking to deepen their understanding of wave behavior in potential wells.

Graham87
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Homework Statement
In which case would you expect the reflection coefficient to largest, for a particle with energy E?

For which of the energy levels would you expect that the tansmission coefficient would be largest?
Relevant Equations
##R=\frac{|A|^2}{|B|^2}##

##T=1-R##

##k=\sqrt{\frac{2m(V_0-E)}{h}}##

##\psi(x)=Ae^{kx}+Be^{-kx}##
5B8339D6-25BE-4C8D-8B2F-C3F02DEAF4B3.jpeg

In a) I get that T should be largest where V_0 is least wide, because when V_0 is infinitely wide the particle would be fully reflected.
But I don't get how height in b) and energy levels height in c) correlates to T and R.

Is it because of their k? I get the opposite answer from the correct one when I plug k in the R formula. ##R=\frac{|A|^2}{|B|^2}##

##T=1-R##

##k=\sqrt{\frac{2m(V_0-E)}{h}}##

##\psi(x)=Ae^{kx}+Be^{-kx}##Thanks!
 
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Graham87 said:
But I don't get how height in b) and energy levels height in c) correlates to T and R.

Is it because of their k? I get the opposite answer from the correct one when I plug k in the R formula.
You need to define what you mean by ##k##. And what formulas are you using for ##T## and ##R##?
 
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vela said:
You need to define what you mean by ##k##. And what formulas are you using for ##T## and ##R##?
Done!
 

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