A study of the efficiency of the class of W -states as a quantum channel

Recently, a new class of W -states has been defined by Agarwal and Pati [23] and it has been shown that they can be used as a quantum channel for teleportation and superdense coding. In this work, we identify those three-qubit states from the set of the new class of W -states which are most efficient or suitable for quantum teleportation. We show that with some probability |W1〉 = 12 (|100〉+ |010〉+ √ 2|001〉) is best suited for teleportation channel in the sense that it does not depend on the input state. PACS Numbers: 03.67.-a, 03.65.Bz,42.50.Dv Quantum teleportation [1] involves the transmission of an arbitrary qubit from one party to another distant party by sending two classical bits. However they must initially share one entangled state. It can also be combined with other operations to construct advanced quantum circuits useful for information processing [2]. The first experimental demonstration of quantum teleportation was reported by Bouwmeester et.al. [3]. Quantum teleportation is also possible in systems corresponding to infinite dimensional Hilbert spaces [5, 6, 7, 8, 9, 10, 11]. The teleportation of quantum entanglement is also known as entanglement swapping [29, 30, 2, 4]. It enables two parties (having no common past) to share quantum entanglement. This protocol may be useful in making nonlocal correlations over long distances. Therefore it can play a significant role in quantum communication. Quantum entanglement [12], the heart of quantum information theory, plays a crucial role in computational and communicational purposes. Therefore as a valuable resource in quantum information processing, quantum entanglement has been widely used in quantum cryptography [13, 14], quantum superdense coding [15], quantum teleportation [1], remote state preparation of special qubits and arbitrary quantum states [16, 17], and teleportation of an unitary operator [18]. Along with Einstein-Podolsky-Rosen (EPR) ∗Corresponding Author: Satyabrata Adhikari, e-mail:[email protected]