"$negfifscattering" 修訂間的差異

於 2018年7月30日 (一) 02:56 的修訂

$negfifscattering is the command to setup the position that stop calculating the scattering. In our code, source electrode is at right side, and drain electrode is at left side, and we calculate from left side to right side. The carrier injection is mainly from source electrode, then we setup the position or according to the third term to determine the position that stop calculating the scattering. The third term is means until initial injection wavefunction decays to what proportion of original, then stop calculating the scattering.
The second term is to setup what kind of scattering of this material. For example, GaAs has polar optical phonon scattering, then we setup the second term is 1 and use $negfpolaropticalphonon command to setup the related parameters; also Si has g-type and f-type intervalley optical phonon scattering, then we setup the second term is 2 and use $negfintervalleyopticalphonon command to setup the related parameters.
Example:

 $negfifscattering
 500 1 0.001
 # Wstop NumIV WstopFactor
 # Note: GaAs --> NumIV=1 (polar optical phonon)
 #         Si --> NumIV=2 (g-type and f-type)

In this case, there are 681 mesh grids from left side(drain) to right side(source). And we setup that after the 500th mesh grid, stop calculating the scattering. Then the code will check what position the initial injection wavefunction decays to 0.001 of original. If the position is smaller than 500, then still calculate the scattering until 500th mesh grid; if the position is larger than 500, then replace the position with new one. Related commands:

 $negfintervalleyopticalphonon, $negfpolaropticalphonon, $negfacousticphonon, $negfsurfaceroughness, $negfionizedimpurity, $negfoverlapcalculation,