Local distinguishability by projective measurement

This paper proves that a set of orthogonal pure states are indistinguishable by restricted local projective measurement and classical communication if the sum of their Schmidt ranks is larger than the dimension of their joint Hilbert space. This result is useful in determining the local distinguishability of quantum states and is stronger in some respects than that of Hayashi et al Phys. Rev. Lett. 96 , 040501. In addition, it presents a new method to determine the local distinguishability of orthogonal states by projecting measurement operators into their subspaces.