| has gloss | eng: In physics, in the area of quantum information theory, Holevos theorem (sometimes called Holevos bound, since it establishes an upper bound) is an important limitative theorem in quantum computing which was published by in 1973. According to the theorem, the amount of information accessible given a quantum state \rho is limited by its Holevo information :S(\rho) -\sum_i}^} p(i) S(\rho_i) where S(\rho)=-\operatornametr}\rho\log_2\rho is the von Neumann entropy, \rho=\sum_i} p(i) \rho_i and \rho_i are the states used to encode the information under the prior distribution p(i). |