Electromagnetic stress-energy tensor is a direct consequence of 3- and 6-dimensional left-and right-helical representations of the Lorentz group

We review 3-d reducible representation of the Lorentz group and introduce a 6-d irreducible representation tailored for transforming 6-d electromagnetic vector, and we show that the mixture of the density matrices associated with the left- and right-helical states is equivalent to the electromagnetic stress-energy tensor.