General Theory of Environment-Assisted Entanglement Distillation

Assisted entanglement distillation

Motivated by the problem of designing quantum repeaters, we study entanglement distillation between two parties, Alice and Bob, starting from a mixed state and with the help of “repeater” stations. To treat the case of a single repeater, we extend the notion of entanglement of assistance to arbitrary mixed tripartite states and exhibit a protocol, based on a random coding strategy, for extracti...

On bound entanglement assisted distillation

We investigate asymptotic distillation of entanglement in the presence of an unlimited amount of bound entanglement for bi-partite systems. We show that the distillability is still bounded by the relative entropy of entanglement. This offers a strong support to the fact that bound entanglement does not improve distillation of entanglement. PACS number(s): 03.65.Bz, 89.70.+c,89.80.+h keywords: e...

Distillation and bound entanglement

Renormalising entanglement distillation

It has long been noted in the field of quantum information science that entanglement constitutes the key resource in various information processing and specifically communication tasks [1]. Secure quantum key distribution necessarily relies on entanglement, even in a sense in prepare and measure schemes [2–4]. One of the main efforts in quantum information science has therefore been directed to...

Compact continuous-variable entanglement distillation.

We introduce a new scheme for continuous-variable entanglement distillation that requires only linear temporal and constant physical or spatial resources. Distillation is the process by which high-quality entanglement may be distributed between distant nodes of a network in the unavoidable presence of decoherence. The known versions of this protocol scale exponentially in space and doubly expon...