Dear Zhang, You can calculate the current for each lead separately (sum over the modes in the lead) and then multiply each current by the corresponding V_i that you obtained from the conductance matrix. Total_current=Sum (current_i *V_i).
You might claim that the dimension is not correct, but keep in mind that what we usually calculate is the transmission probability and thus we need to multiply by V (and the quantum of conductance) to get the current in the linear response theory. This will give you, *qualitatively*, the current map in your system. (I am interested to see the result) I hope this helps, Adel On Wed, May 1, 2024 at 12:23 PM X.-X. Zhang <xiaoxiao.zh...@riken.jp> wrote: > Hello Kwant community, > I am considering a 6-terminal sample with 0,1,2,3 the voltage leads and > 4,5 the current lead. Normally, with the conductance_matrix M found by > kwant I can calculate transport properties (the voltages in vector V) as > per the linear equation I = M V, given I = [0,0,0,0,1,-1]. > > Now I want to plot the current density corresponding to this transport > state, but not sure how to do it. > > For instance, with wf = kwant.wave_function(sys, energy), I can have all > scattering wavefunctions wf(4) incoming from the current lead 4. But how to > (or is it necessary to) reflect the above current configuration vector I we > specified? I presume the current density may vary with different I vectors. > Or maybe I misunderstand some basics? > > Thank you! > -- Abbout Adel