Exploiting quantum mechanics for transmitting information is a tantalizing possibility because it promises secure, high speed communications.
Unfortunately, the fragility of methods for storing and sending quantum information has so far frustrated the enterprise. Now a team of physicists in Sweden and Poland have shown that photons that encode data have strength in numbers. Their experiment is reported in Physical Review Letters and Physical Review A and highlighted in the October 5 issue of Physics (physics.aps.org).
In classical communications, a bit can represent one of two states - either 0 or 1. But because photons are quantum mechanical objects, they can exist in multiple states at the same time. Photons can also be combined, in a process known as entanglement, to store a bit of quantum information (i.e. a qubit).
Unlike data stored in a computer or typically sent through conventional fiber optic cables, however, qubits are extremely fragile. A kink in a cable, the properties of the cable material, or even changes in temperature can corrupt a qubit and destroy the information it carries. But now a group lead by Magnus Rådmark at Stockholm University has shown that six entangled photons can encode information that stands up to some knocking around.
Rådmark and his team proved experimentally that their six photon qubits are robust and should be able to reliably carry information over long distances. The technology to encode useful information on the qubits and subsequently read it back is still lacking, but once those problems are solved, we will be well on our way to secure, reliable, and speedy quantum communication.
Also in Physics: Quasiparticles do the twist
Joel Moore writes a Viewpoint on a paper examining the experimental evidence for oddball particles that don't behave like either fermions or bosons, the two breeds of particles in quantum mechanics.
About APS Physics: APS Physics (http://physics.aps.org) publishes expert written commentaries and highlights of papers appearing in the journals of the American Physical Society. Here are some of the papers that will be featured in this week's issue of APS Physics.
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DGIST develops 20 times faster biosensor
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More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
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The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
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