Remote Quantum-Information Concentration: Reversal of Ancilla-Free Phase-Covariant Telecloning

Abstract

Telecloning and its reverse process, referred to as remote quantum-information concentration (RQIC), have been attracting considerable interest because of their potential applications in quantum-information processing. The previous RQIC protocols were focused on the reverse process of the optimal universal telecloning. We here study the reverse process of ancilla-free phase-covariant telecloning (AFPCT). It is shown that the quantum information originally distributed into two spatially separated qubits from a single qubit via the optimal AFPCT procedure can be remotely concentrated back to a single qubit with a certain probability by using an asymmetric W state as the quantum channel.

Controlled Remote Information Concentration via Non-Maximally Entangled GHZ-Type States

“…So that it is of great interest and significance to investigate some non-maximally entangled quantum states how to work as quantum channel in quantum process. Recently, base on the study of Wang and Tang [28], in which they proposed a scheme for implementing 2 −→ 1 RQIC via a tripartite asymmetric W state as quantum channel, i.e., the reversal of the optimal ancillafree phase-covariant telecloning(AFPCT), Bai et al [36] have proposed some schemes of 3 −→ 1 remote quantum information concentration via non-maximally entangled GHZ states. And those schemes can realized with certain probability relative to the parameters of the non-maximally entangled GHZ state, which are used as quantum channel in those schemes.…”

“…Since Murao and Vedral proposed the first original scheme of quantum remote information concentration, almost all of maximally entangled states, such as Bell states [20,21], GHZ states [22][23][24][25], W states [26][27][28] and the other entangled states [29][30][31][32][33] were employed as quantum channel in different schemes. Nevertheless, in practice, the coupling of the quantum state and the surrounding environment are inevitable, thus those maximally entangled quantum states that are used as quantum channel in quantum works are difficult to be generated.…”

Controlled Remote Information Concentration via GHZ-type States

“…From then on, More and more people devote themselves to studying in this field [19][20][21]. Recently, Wang and Tang have proposed a scheme for the reversal of ancillafree phase-covariant telecloning via W states [22]. Based on this study of Wang, Bai et al, have proposed some schemes of remote quantum information concentration via GHZ-type states [23].…”