Physics is fascinating because of the intellectual excitement it provides and because of the applications it offers. In the Group of Applied Physics (GAP) at Geneva University we get our inspiration from both of these motivations. Optics, in this respect, has a privileged place. Indeed, in modern optics, experiments and theory progress hand-in-hand, and practical applications are close behind. Consequently, we can work both on conceptual issues and on applications. Moreover, it is a very good time for optics! The fascinating new insight about quantum mechanics brought about by recent quantum optics experiments on one side, and the tremendous development of optical communications on the other, illustrates our privileged position!
The American Research Council has recently declared optics as the technology of the 21st century. In contrast, a famous physicist, Michael Berry, has declared that the 21st century will be shaped by quantum physics, in a way similar to electrodynamics, which shaped the 20th century. Our position in GAP-Quantique, at the crossroads between optics and quantum physics, ensures our participation to both challenges.
Harnessing nonlinearities strong enough to allow single photons to interact with one another is not only a fascinating challenge but also central to numerous advanced applications in quantum information science. We recently realised the first nonlinear interaction between two single photons. Each photon is generated in independent parametric down-conversion sources. They are subsequently combined in a nonlinear waveguide where they are converted into a single photon of higher energy by the process of sum-frequency generation. Our approach results in the direct generation of photon triplets. More generally, it highlights the potential for quantum nonlinear optics with integrated devices and, as the photons are at telecom wavelengths, it opens the way towards novel applications in quantum communication such as device-independent quantum key distribution.
We are very pleased that this work has been published in the Physical Review Letters. The letter can be found on our website. It was also highlighted by the Editors and received a Viewpoint article, Two Photons into One.
Entanglement in our experiment is established between a rare-earth-ion doped crystals storing a single photon that is polarization-entangled with a flying telecom-wavelength photon. The latter is jointly measured with another flying qubit carrying the polarization state to be teleported, which heralds the teleportation.
We also performed teleportation in a configuration where the combined distance travelled by both telecom-wavelength photons is 25 km in standard optical fibre while still outperforming the classical benchmark, demonstrating the long-distance capability of our approach.
Our experiment demonstrates the feasibility of long-distance teleportation of a single quanta of light onto a solid-state quantum memory. The fundamentals of our experiment could be used to demonstrate a small-scale network of remote quantum memories, or a real-world quantum repeater based on an optical-fibre architecture.
Prof. Nicolas Gisin has been awarded the Marcel Benoist Prize 2014 - the Swiss science award - for his outstanding work on the theoretical foundations and possible applications of quantum mechanics and quantum cryptography. He is considered to be one of the founders and leading researchers in the field, as well as one of the most cited scientists. His theoretical and, above all, his experimental research has produced decisive impulses for further developments in this field of research.
The experiment successfully conducted by Nicolas Gisin on quantum entanglement between Bernex and Bellevue is considered by the American Physical Society to be one of the most important scientific milestones of the 20th century. In 2003 the Technology Review of Massachusetts Institute of Technology MIT included his work on quantum cryptography among the ten most seminal inventions.
Nicolas Gisin's work has enabled other research groups to follow in his footsteps and continue to develop this field of research. His findings are not limited only to basic research, but have also, through applied research, enabled various start-ups to offer marketable products and services in the field of data protection, for example.
The official ceremony to award the Marcel Benoist Prize will be held in Geneva on 29 October. The prize, considered to be Switzerland's 'Nobel Prize', has been awarded every year since 1920 to a scientist based in Switzerland for their the most useful scientific discovery or study, in particular in disciplines which are of significance for human life (further information about the prize can be found at http://www.marcel-benoist.ch). Over the course of its almost hundred year history, 10 laureates have gone on to win a Nobel Prize.
In an interview at Radio Télévision Suisse Professor Nicolas Gisin, the winner of the Marcel Benoist prize, the swiss Science 2014 prize, discusses his scientific research in the field of quantum physics and potential applications of quantum mechanics and quantum cryptography.
Nicolas Gisin, professeur de physique à l’Université de Genève, est le lauréat du Prix Marcel Benoist 2014 pour ses travaux sur les fondements et les applications possibles de la mécanique et de la cryptographie quantiques.
Listen to the interview in two parts here:
Prof. Nicolas Gisin has been honored by the 2014 Quantum Communication Award “for his pioneering contributions to the advancement of quantum communications, quantum cryptography, and related technologies” . The prize will be presented at the Conference on Quantum Communication, Measurement and Computing (QCMC) XII in November in China.