Entanglement cost of antisymmetric states and additivity of capacity of some quantum channels

Abstract

We study the entanglement cost of the states in the contragredient space,\nwhich consists of $(d-1)$ $d$-dimensional systems. The cost is always $\\log_2\n(d-1)$ ebits when the state is divided into bipartite $\\C^d \\otimes\n(\\C^d)^{d-2}$. Combined with the arguments in \\cite{Matsumoto02}, additivity of\nchannel capacity of some quantum channels is also shown.\n