function [JCharge,JSpin,Jsp, JspR,JTIS,JFull,JEmpty] = driftCurrent( EkT,x )
% it calculates drift band current in absence of any standing wave
% electrons. It is simple derivitive of SpinStatistics in respect of energy
%
% [JCharge JSpin Jsp JspR JTIS JFull JEmpty] = driftCurrent( EkT,x )
% x is spin polarization  EkT  is electron energy /kT
%JCharge  is the charge curent
%JSpin  is the spin curent or current of spin-polarized electrons (spin
%injection)
% Jsp is the spin polarization of the drift current
% Jsp is the ratio of spin polarization of the drift current to the spin
% polarization of the electron gas
% JTIS is the current of spin-unpolarized electrons, which occupies
% half-filled state
% stFull - is the current of spin-unpolarized electrons, which occupies
% full-filled state
%stEmpty is the current of states, which are not filled
% 
% use for gragh EkT=-5:0.05:5; EkT=EkT';
%M(:,1)=EkT(:);M(:,2)=JCharge(:);M(:,3)=JSpin(:);M(:,4)=JTIS(:);M(:,5)=JFull(:);M(:,6)=Jsp(:);M(:,7)=JspR(:);
%
%        


JCharge=zeros(length(EkT),length(x));
JSpin=zeros(length(EkT),length(x));
Jsp=zeros(length(EkT),length(x));
JspR=zeros(length(EkT),length(x));
JTIS=zeros(length(EkT),length(x));
JFull=zeros(length(EkT),length(x));
JEmpty=zeros(length(EkT),length(x));

dE=0.0001; % step to take derivation

for jE=1:length(EkT)

    for jx=1:length(x)
[ TIA1, TIS1, stFull1, ~, stEmpty1, ~] = SpinStatistic( EkT(jE)+dE,x(jx));
[ TIA2, TIS2, stFull2, ~, stEmpty2, ~] = SpinStatistic( EkT(jE)-dE,x(jx));

JTIA(jE,jx)=-(TIA1-TIA2)/2/dE;
JTIS(jE,jx)=-(TIS1-TIS2)/2/dE;
JFull(jE,jx)=-(stFull1-stFull2)/2/dE;
JEmpty(jE,jx)=-(stEmpty1-stEmpty2)/2/dE;
JCharge(jE,jx)=JTIA(jE,jx)+JTIS(jE,jx)+JFull(jE,jx);
JSpin(jE,jx)=JTIA(jE,jx);
Jsp(jE,jx)=JSpin(jE,jx)/JCharge(jE,jx);
JspR(jE,jx)=Jsp(jE,jx)/x(jx);
    end
end







end