The transverse magnetic injection is a periodic injection which has the effect of driving the system. The injection is added onto the equation for the number of carriers:
We have two extra parameters here. One is 
, which can be
broken down into 
. Here 
is the frequency of the
periodic injection we are putting into the system. The other term b, is the strength of injected
field which we are free to vary. The injection has the effect of making the system act perodic.
Our aim is to fix the value for and let b be our control parameter. How do you choose the
right ? This will be explained next.