Asymmetric quantum telecloning ofd-level systems and broadcasting of entanglement to different locations using the “many-to-many” communication protocol

Abstract

We propose a generalization of quantum teleportation: the so-called many-to-many quantum communication of the information of a d-level system from N spatially separated senders to M > N receivers situated at different locations. We extend the concept of asymmetric telecloning from qubits to d-dimensional systems. We investigate the broadcasting of entanglement by using local 1 → 2 optimal universal asymmetric Pauli machines and show that the maximal fidelities of the two final entangled states are obtained when symmetric machines are applied. Cloning of entanglement is studied using a nonlocal optimal universal asymmetric cloning machine and we show that the symmetric machine optimally copies the entanglement. The "many-to-many" teleportation scheme is applied in order to distribute entanglement shared between two observers to two pairs of spatially separated observers.

A generalization of quantum teleportation and splitting of entanglement via local cloning

“…Cerf has found the expression of the optimal universal asymmetric cloning machine of d-level states using a reference state [9]. We have also obtained an equivalent expression of this cloning machine, by eliminating the reference state [5]:…”

“…with p+q = 1, where theˇrst two qubits represent the clones and the last one is the ancilla [5]. The initial entanglement shared by two observers, Alice and Bob, is:…”

“…, A N . We would like to distribute this information to M receivers located at different places [5]. The initial entangled state is The quantum channel is deˇned as a maximally entangled (N + M )-particle state shared between senders and receivers:…”

A Proposal of Telecloning for a Three-Particle Entangled W State

“…With the great advances in quantum cryptography, quantum remote control and distributed quantum computing, the effective proposals for transmission, manipulation and storage of quantum information are required, which can be achieved by utilizing the capability of creating and manipulating of nonlocal multipartite quantum entanglement. So, there has been a steadily growing interest in telecloning and telebroadcasting for quantum entangled states [17][18][19][20]. Compared with the scheme in Ref.…”

Quantum Chernoff bound as a measure of the efficiency of quantum cloning for mixed states

“…Both symmetric and asymmetric cloning machine of pure states are of great importance in a process called quantum telecloning that enables the transmission of the imperfect clones at a distance [11]. This protocol was extended to the symmetric case for d-level systems and asymmetric telecloning of qubits [12,13], as well as asymmetric telecloning of qudits [14]. A different generalization of telecloning consists of using a non-maximally entangled channel as a resource [15,16,17].…”