QUCOMM: Long Distance photonic quantum communication

• Research unit: EU RFP
• Project number: 99.0154

Key words (English)

Photonic quantum communication

Alternative project number (English)

EU project number: IST-1999-10033

Research programs (English)

EU-programme: 5. Frame Research Programme - 1.2.8 Generic R&D activities

Short description (English)

See abstract

Partners and International Organizations (English)

Coordinator: Kungliga Tekniska Högskolan (S)

Abstract (English)

All communication channels are at bottom quantum mechanical. This project aims at exploring the positive side of this fact. In particular, we develop the understanding and the technology to exploit entanglement in order to achieve communication tasks that would be impossible using only classical channels. Recall that entanglement is a purely quantum feature of composed systems; and it is this feature that makes quantum physics so different from classical intuition: the whole is more than the sum of the parts.
In 2001, during a collaboration with the US Los Alamos Laboratories, we experimentally demonstrated for the first time 'entanglement concentration', that is the possibility to act locally on two distant photons is such a way that the photons pasing this non-local filter are more entangled than the incoming photons. This work appeared in Nature (409, 1014-1017, 2001).
The second important work carried out at Geneva University concerns the experimental realization of a protocol called 'entaglement swapping' in which two photons that never interacted get entangled. On the long term this could be the building block of quantum repeater, with the potential of extending quantum communication, in particular quantum cryptography, to arbitrary long distances.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 99.0154