Non-maximally Entangled Mixed States of X and Non-X Types as Teleportation Channels

Mixed spin-1/2 states violating Bell-CHSH inequality is useful for teleportation. There exist states which do not violate Bell-inequality but is still useful as teleportation channels. Maximally entangled mixed states of Munro class and Ishizaka-Hiroshima class are such types which although satisfy Bell-CHSH inequality, yet can perform better as teleportation channels for a given degree of mixedness (Adhikari et al., Quant. Inf. Comp. 10, 039, 2010). In this work we construct class of mixed states of non-maximally entangled types whose efficacy as teleportation channels have been studied. For certain range of state parameters, these non-maximally entangled mixed states performs better as quantum teleportation channels than certain maximally entangled mixed states (such as Werner state). These constructed states, though entangled, satisfy Bell-CHSH inequality implying further that violation of local inequalities may not be good indicators of their ability to complete quantum processing tasks such as teleportation.