Class HaynesShockley

java.lang.Object
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  +--TimeDepSchrodinger
        |
        +--HaynesShockley

class HaynesShockley

extends TimeDepSchrodinger

Class to model the Haynes-Shockley experiment. Uses the fourth-order Runge-Kutta method to interpolate across time.

Field Summary

protected double	field The field strength
protected double	lifetime The carrier lifetime
protected double[]	p The function data

Fields inherited from class TimeDepSchrodinger

dt, energy, h, pot, potFn, psi, t, width, x0

Constructor Summary

HaynesShockley()

Method Summary

protected void	advanceOnce(double dt) Performs one step of the Runge-Kutta method.
double	getField() Returns the selected field strength
double	getLifetime() Returns the selected carrier lifetime
void	initFunction(double x, double h, int steps) Resets the model, replacing the function data with a new square wave.
double	integralCheck() Approximates the integral of the function, by summing the function data and dividing by h.
void	setField(double d) Sets the selected field strength
void	setLifetime(double d) Sets the selected carrier lifetime
void	solve(double x, double h, double[] vals) Since all the work is done in advanceOnce(), this method need only return the function data.
protected double	xderiv(double[] d, int i) Measures the derivative with respect to x using a finite difference method.
protected double	xderiv2(double[] d, int i) Measures the second derivative with respect to x using a finite difference method.

Methods inherited from class TimeDepSchrodinger

advanceOnce, getEnergy, getT, getWidth, getX0, setEnergy, setT, setWidth, setX0, xderiv

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait

Field Detail

lifetime

protected double lifetime

The carrier lifetime

field

protected double field

The field strength

p

protected double[] p

The function data

Constructor Detail

HaynesShockley

public HaynesShockley()

Method Detail

initFunction

public void initFunction(double x,
                         double h,
                         int steps)

Resets the model, replacing the function data with a new square wave.

Overrides:

initFunction in class TimeDepSchrodinger

Parameters:

x - The smallest x-value to consider

h - The gap between x-values

steps - The number of x-values to consider

advanceOnce

protected void advanceOnce(double dt)

Performs one step of the Runge-Kutta method.

Overrides:

advanceOnce in class TimeDepSchrodinger

Parameters:

dt - The size of the advancement in time

xderiv

protected double xderiv(double[] d,
                        int i)

Measures the derivative with respect to x using a finite difference method. If the region considered touches the edge of the function data (so i <= 1 or i >= d.length-2, zero will be returned.

Parameters:

d - The function data on which to operate

i - The index at which the derivative is required

Returns:

(d[i+1]-d[i-1])/2h

xderiv2

protected double xderiv2(double[] d,
                         int i)

Measures the second derivative with respect to x using a finite difference method. If the region considered touches the edge of the function data (so i <= 1 or i >= d.length-2, zero will be returned.

Parameters:

d - The function data on which to operate

i - The index at which the derivative is required

Returns:

(d[i+1]+d[i-1]-2d[i])/(h*h)

solve

public void solve(double x,
                  double h,
                  double[] vals)

Since all the work is done in advanceOnce(), this method need only return the function data. Since it is not practical to adjust the size or x-spacing of the data in the array while the simulation is running, the x and h parameters are ignored.

Overrides:

solve in class TimeDepSchrodinger

Throws:

java.lang.RuntimeException - if vals is not the same size as the array of function data

integralCheck

public double integralCheck()

Approximates the integral of the function, by summing the function data and dividing by h.

Overrides:

integralCheck in class TimeDepSchrodinger

getField

public double getField()

Returns the selected field strength

setField

public void setField(double d)

Sets the selected field strength

getLifetime

public double getLifetime()

Returns the selected carrier lifetime

setLifetime

public void setLifetime(double d)

Sets the selected carrier lifetime