Quantum communication is one of the central themes at GAP. From seminal QKD experiments under lake Geneva to teleportation experiments in real-world communication networks, The GAP in Geneva has become synonymous with quantum communication. Central to many of these endeavours is entanglement, which provides us with somewhat of a leitmotif - that entanglement is not only fascinating, but also useful – a resource.

For more than a decade, we have endeavoured to demonstrate this, not only in the lab but also with the view that, to be useful, it has to survive in the real world. This requires making some compromises, but often, this has also pushed us towards new and exciting directions and opened up opportunities to perform foundational experiments, or on the other end of the spectrum, industrialise quantum technologies.

Recently, the concept of Device-Independent, or Self-Testing, quantum systems has been proposed, again a concept that bridges fundamental and applied physics. These new concepts place extremely demanding constraints on all the component technologies, such as photon pair sources, single photon detectors and even quantum circuits and channels themselves. Some of our recent work can be found by following the links below.

Contact: Rob Thew

Team: Hugo Zbinden, Nicolas Sangouard, Bruno Sanguinetti, Anthony Martin, Natalia Bruno, Thiago Guerreiro, Fernando Monteiro

We have recently published the theoretical model for a novel SPDC source based on an integrated OPO using a PPLN waveguide, where single narrow-band, possibly distinct, resonant modes for the idler and the signal fields can be generated. This mode selection takes advantage of the clustering effect, due to the intrinsic dispersion of the nonlinear material Read More

We have recently been working on nonlinear optics at the single photon level. This seemingly low efficiency process can have some fascinating advantages. Read More

For older work from the quantum communication group, check out our Work Archive

MHz rate and efficient synchronous heralding of single photons at telecom wavelengths, Enrico Pomarico et al. Opt. Exp. 20, 23846 (2012)

Heralded photon amplification for quantum communication, Clara Osorio et al. Phys. Rev. A, 86, 023815 (2012)

Engineering integrated pure narrow-band photon sources, Enrico Pomarico et al. New J. Phys 14, 033008 (2012)

Faithful Entanglement Swapping Based on Sum-Frequency Generation, Nicolas Sangouard et al. Phys. Rev. Lett. 106, 120403 (2011)

Coherent frequency-down-conversion interface for quantum repeaters, Noé Curtz et al., Opt. Expr. 18, 22099 (2010)

Purification of Single-Photon Entanglement, D. Salart et al., Phys. Rev. Lett. 104, 180504 (2010)

Here are a couple of popular articles on quantum communication and the associated technologies:

Quantum communication technology, N Gisin, R T Thew, Electronics Letters, 46, 965 (2010)

Quantum communication, Nicolas Gisin, Rob Thew, Nature Photonics, 1, 165 (2007)

Nonlinear Optics, Stanford University (Prof. Martin Fejer & Jason Pelc)

Quantum Technologies Group, University of Oxford (Dr Brian Smith)

Applied Physics: Integrated Quantum Optics, University of Paderborn (Prof. Christine Silberhorn)

Q-ESSENCE

ERC-QORE

NCCR: QSIT - Quantum Science and Technology

NCCR: Quantum Photonics

Left to right: Nicolas Gisin, Clara Osorio, Rob Thew, Hugo Zbinden, Enrico Pomarico, Bruno Sanguinetti, Natalia Bruno, Thiago Guerreiro

And more Quantum Communication Group photos!