I want to define T shape gate
I added material air in free space , But it is showing boundry condition not defined
electrode num=3 name=gate mat=gold x.min=2.6 x.max=3.5 y.min=0.03 y.max=0
electrode num=4 name=gate mat=gold x.min=2.8 x.max=3.3 y.min=0.03 y.max=0.15