Optimal sequence of POVMs in the sense of Stein's lemma in quantum hypothesis testing

In this paper, we give another proof of quantum Stein's lemma by calculating the information spectrum, and study an asymptotic optimal measurement in the sense of Stein's lemma. We propose a projection measurement characterized by the irreducible representation theory of the special linear group SL(H). Specially, in spin 1/2 system, it is realized by a simultaneous measurement of the total momentum and a momentum of a specified direction.