"Quantum scattering"의 두 판 사이의 차이

수학노트
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5번째 줄: 5번째 줄:
 
* continuous spectrum <math>\lambda>0</math>
 
* continuous spectrum <math>\lambda>0</math>
 
* for lists [http://en.wikipedia.org/wiki/Delta_potential_barrier_%28QM%29 http://en.wikipedia.org/wiki/Delta_potential_barrier_(QM)]
 
* for lists [http://en.wikipedia.org/wiki/Delta_potential_barrier_%28QM%29 http://en.wikipedia.org/wiki/Delta_potential_barrier_(QM)]
 
 
 
  
 
 
 
 
16번째 줄: 14번째 줄:
 
* [[Schrodinger equation]]<br><math>E \psi = -\frac{\hbar^2}{2m}{\partial^2 \psi \over \partial x^2} + V(x)\psi</math><br>
 
* [[Schrodinger equation]]<br><math>E \psi = -\frac{\hbar^2}{2m}{\partial^2 \psi \over \partial x^2} + V(x)\psi</math><br>
 
*  simplified form<br><math>-\varphi_{xx}+u(x)\varphi = \lambda\varphi</math><br><math>\varphi_{xx}+(\lambda-u(x))\varphi=0</math><br>
 
*  simplified form<br><math>-\varphi_{xx}+u(x)\varphi = \lambda\varphi</math><br><math>\varphi_{xx}+(\lambda-u(x))\varphi=0</math><br>
 
 
 
  
 
 
 
 
57번째 줄: 53번째 줄:
 
 
 
 
  
<h5>example</h5>
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<h5>sech potential example</h5>
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#  
 
# \[Lambda] := -1<br> u[x_] := -2 Sech[x]^2<br> f[x_] := Sech[x]<br> Simplify[D[D[f[x], x], x] + (\[Lambda] - u[x]) f[x]]<br> Plot[u[x], {x, -5, 5}]
 
# \[Lambda] := -1<br> u[x_] := -2 Sech[x]^2<br> f[x_] := Sech[x]<br> Simplify[D[D[f[x], x], x] + (\[Lambda] - u[x]) f[x]]<br> Plot[u[x], {x, -5, 5}]
  

2011년 2월 14일 (월) 08:36 판

introduction

 

 

time independent Schrodinger equation
  • Schrodinger equation
    \(E \psi = -\frac{\hbar^2}{2m}{\partial^2 \psi \over \partial x^2} + V(x)\psi\)
  • simplified form
    \(-\varphi_{xx}+u(x)\varphi = \lambda\varphi\)
    \(\varphi_{xx}+(\lambda-u(x))\varphi=0\)

 

continuous spectrum
  • e^{ikx} represents a wave traveling to the right, and e^{−ikx} one traveling to the left
  • e^{−ikx} is incoming wave from the right to the left
  • reflection and transmission coefficient
    \(\varphi \sim e^{-ikx}+\rho(k,t)e^{ikx}\) as \(x\to +\infty\)
    \(\varphi \sim \tau(k,t)e^{-ikx}\) as \(x\to -\infty\)
    \(\rho(k,t)\) and \(\tau(k,t)\) are called the reflection and transmission coefficient

 

potential scattering

\(r=t-1\)

If t is of the form \(t=\frac{1}{1-ai}\) (real number a), then

\(|r|^2+|t|^2=1\)

 

 

delta potential example

 

 

harmonic oscillator

 

 

sech potential example

 

 

  1.  
  2. \[Lambda] := -1
    u[x_] := -2 Sech[x]^2
    f[x_] := Sech[x]
    Simplify[D[D[f[x], x], x] + (\[Lambda] - u[x]) f[x]]
    Plot[u[x], {x, -5, 5}]

 

 

 

history

 

 

related items

 

 

encyclopedia

 

 

books

 

 

 

expositions

 

 

 

articles

 

 

question and answers(Math Overflow)

 

 

blogs

 

 

experts on the field

 

 

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