Quantum scattering

수학노트
http://bomber0.myid.net/ (토론)님의 2011년 2월 8일 (화) 12:37 판
둘러보기로 가기 검색하러 가기
introduction

 

 

 

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

 

 

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

 

delta potential example

\(V(x) = \lambda\delta(x)\)

\(\psi(x) = \begin{cases} \psi_{\mathrm L}(x) = A_{\mathrm r}e^{ikx} + A_{\mathrm l}e^{-ikx}, & \text{ if } x<0; \\ \psi_{\mathrm R}(x) = B_{\mathrm r}e^{ikx} + B_{\mathrm l}e^{-ikx}, & \text{ if } x>0, \end{cases}\)

 

harmonic oscillator

 

 

example
  1. \[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

 

 

links