In this issue: Foiling Quantum Hackers, Are Neutrinos Their Own Antiparticles?, Friction at the Atomic Scale
---------------------------
Foiling Quantum Hackers
Researchers have implemented a new quantum encryption method that may provide the ultimate security against hackers in real-world cryptography applications.
Quantum cryptography holds promise for communication schemes that are, in theory, perfectly secure because they are protected by the fundamental laws of quantum mechanics: an eavesdropper cannot measure photons without disturbing their delicate quantum properties – and being noticed in the process. But in the last few years, hackers have exploited security loopholes to crack some of the most sophisticated quantum encryption systems. Now, two independent teams of researchers (the first based in China, the second in Canada) have implemented a new quantum encryption method that removes the most problematic link of quantum encryption schemes: weaknesses of the detectors used at the receiver end.
* Y Liu, Qiang Zhang (contact author) et al, “Experimental measurement-device-independent quantum key distribution”, Physical Review Letters
** A Rubenok, Joshua A Slater (contact author) et al, “Real-world two-photon interference and proof-of-principle quantum key distribution immune to detector attacks”, Physical Review Letters
(expected publication date: Sep 23)
---------------------------
Are Neutrinos Their Own Antiparticles?
A new study disproves the results of a 2004 experiment that claimed to show the neutrino and the antineutrino are the same particle.
In the 1930s, the physicist Ettore Majorana suggested neutrinos might be their own antiparticle. The idea is in conflict with the standard model of particle physics, but might help explain certain properties of neutrinos, such as their small mass. If the hypothesis is true, neutrinos may annihilate with each other and disappear in a rare nuclear reaction known as “double beta decay”, in which two neutrons decay into a pair of protons. In experiments carried out in 2004, physicists argued they had seen signs of such neutrino-less decays, but now the GERDA collaboration at the Gran Sasso National Laboratory in Italy has conclusively refuted the earlier results. The researchers built a device with unprecedented sensitivity to the rare decay, showing that the rate of neutrino-less double beta decay—if it occurs at all—is less than a part in ten thousand of that of normal double beta decay.
* The GERDA collaboration (contact author: Peter Grabmayr), “Results on neutrinoless double-β decay of 76-Ge from phase I of the GERDA experiment”, Physical Review Letters (expected publication date:Sep 19)
---------------------------
Friction at the Atomic Scale
Researchers from Germany and the Czech Republic have demonstrated a new experimental method based on atomic force microscopy (AFM) that allows the investigation of friction at the scale of individual atoms.
* Jay Weymouth (contact author) et al, “Atomic structure affects the directional dependence of friction”, Physical Review Letters (expected publication date: Sep 18)
---------------------------
Journal articles and preprints are available to journalists on request.
Matteo Rini, PhD
Deputy Editor, Physics
