function [ U ] = CUE2( )
%CUE2 constructing 2x2 CUE matrix via explicit parametrization

a = rand(1,4);
p2 = 2i*pi;
c = sqrt(1-a(1));
s = sqrt(a(1));
chi = exp(p2*a(2));
f1 = exp(p2*a(3));
f2 = exp(p2*a(4));

U = [c, -chi'*s;
    chi*s, c] ...
    * ...
    [f1, 0;
    0, f2];

end

