Wave Propagation in Linear Media | re-examined
Wave Propagation in Linear Media | re-examined
Wave Propagation in Linear Media | re-examined
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A.2 Solutions for the step potential<br />
OscInt[f<strong>in</strong>t_, fzero_, a_, opts___Rule] :=<br />
OscInt[f<strong>in</strong>t,fzero,{a,a},opts]<br />
End[]<br />
SetAttributes[PolynomialDeg<strong>re</strong>e, ReadProtected]<br />
SetAttributes[AsymptoticExpand, ReadProtected]<br />
SetAttributes[ApproxLimGeneric, ReadProtected]<br />
SetAttributes[ApproxLimQuad, ReadProtected]<br />
SetAttributes[ApproxLimL<strong>in</strong>ear, ReadProtected]<br />
SetAttributes[QuadZero, ReadProtected]<br />
SetAttributes[QuadOffset, ReadProtected]<br />
SetAttributes[HypZero, ReadProtected]<br />
SetAttributes[HypOffset, ReadProtected]<br />
SetAttributes[HypZeroExact, ReadProtected]<br />
SetAttributes[HypOffsetExact, ReadProtected]<br />
SetAttributes[ZerosInBetween, ReadProtected]<br />
SetAttributes[HypApproxError, ReadProtected]<br />
SetAttributes[PartInt, ReadProtected]<br />
SetAttributes[PartitionTable, ReadProtected]<br />
SetAttributes[PartitionOffs, ReadProtected]<br />
SetAttributes[PartitionPo<strong>in</strong>ts, ReadProtected]<br />
SetAttributes[OscInt, ReadProtected]<br />
SetAttributes[OscIntControlled, ReadProtected]<br />
(*<br />
Protect[PolynomialDeg<strong>re</strong>e, AsymptoticExpand, ApproxLimGeneric]<br />
Protect[ApproxLimQuad, ApproxLimL<strong>in</strong>ear]<br />
Protect[QuadZero, QuadOffset]<br />
Protect[HypZero, HypOffset]<br />
Protect[HypZeroExact, HypOffsetExact]<br />
Protect[ZerosInBetween, HypApproxError]<br />
Protect[PartInt, PartitionTable, PartitionOffs, PartitionPo<strong>in</strong>ts]<br />
Protect[OscInt, OscIntControlled]<br />
*)<br />
EndPackage[]<br />
A.2 Solutions for the step potential<br />
The package Tunnel computes the solutions of the Schrod<strong>in</strong>ger equation for the step potential<br />
barrier discussed <strong>in</strong> section 4.3. Its structu<strong>re</strong> is expla<strong>in</strong>ed <strong>in</strong> chapter 8. For the calculation of<br />
the <strong>in</strong>tegrals, the package OscInt is used.<br />
(* Copyright: Copyright 1996, Institute of Computertechnology, *)<br />
(* Vienna University of Technology *)<br />
(*:Version: Mathematica 2.2.3 *)<br />
(*:Title: Tunnel *)<br />
(*:Author: Thilo Sauter *)<br />
(*:Keywords: Tunnel Effect *)<br />
(*:Requi<strong>re</strong>ments: None. *)<br />
(*:Warn<strong>in</strong>gs: None so far *)<br />
(*:Packages: OscInt *)<br />
(*:Summary: This package conta<strong>in</strong>s functions for the time-dependent solutions<br />
of Schroed<strong>in</strong>ger's equation. The exact solution has been evaluated<br />
for wave packet imp<strong>in</strong>g<strong>in</strong>g on a given step potential barrier. The<br />
<strong>in</strong>itial shape of the wave packet can be either <strong>re</strong>ctangular,<br />
triangular, or Gaussian. The solution of the diffe<strong>re</strong>ntial<br />
equation consists of Fourier <strong>in</strong>tegrals and must be evaluated<br />
numerically. A seve<strong>re</strong> obstacle to a straightforward <strong>in</strong>tegration<br />
a<strong>re</strong> the heavily oscillat<strong>in</strong>g <strong>in</strong>tegrands. Thus <strong>in</strong>tegration is<br />
carried out by us<strong>in</strong>g the functions <strong>in</strong> the package OscInt<br />
*)<br />
(*:History: 15-11-1996 written<br />
25-01-1997 templates added<br />
02-02-1997 new nam<strong>in</strong>g convention for functions<br />
17-02-1997 truncation quadratu<strong>re</strong> of Gaussian waves added<br />
*)<br />
Beg<strong>in</strong>Package["Tunnel`", "OscInt`"]<br />
Phi::usage =<br />
"Phi[x,t,w,k,(n),(opts)] <strong>re</strong>turns the wave function at a given coord<strong>in</strong>ate<br />
<strong>in</strong> space and time. The shape of the <strong>in</strong>cident wave is selected with the option<br />
Shape. The step barrier is supposed to beg<strong>in</strong> at x=0. Depend<strong>in</strong>g on the spatial<br />
221