Contact: Michael Bishop
Institute of Physics
Albert Einstein famously described quantum entanglement as “spooky action at distance”; however, up until now experiments that examine this peculiar aspect of physics have been limited to relatively small distances on Earth.
In a new study published today, 9 April, in the Institute of Physics and German Physical Society’s New Journal of Physics, researchers have proposed using the International Space Station (ISS) to test the limits of this “spooky action” and potentially help to develop the first global quantum communication network.
Their plans include a so-called Bell experiment which tests the theoretical contradiction between the predictions of quantum mechanics and classical physics, and a quantum key distribution experiment which will use the ISS as a relay point to send a secret encryption key across much larger distances than have already been achieved using optical fibres on Earth.
Their calculations show that “major experimental goals” could already be achieved with only a few overhead passes of the ISS, with each of the experiments lasting less than 70 seconds on each pass.
“During a few months a year, the ISS passes five to six times in a row in the correct orientation for us to do our experiments. We envision setting up the experiment for a whole week and therefore having more than enough links to the ISS available,” said co-author of the study Professor Rupert Ursin from the Austrian Academy of Sciences.
Furthermore, the only equipment needed aboard the ISS would be a photon detection module which could be sent to the ISS and attached to an already existing motorised commercial photographer’s lens (Nikon 400 mm), which sits, always facing the ground, in a 70 cm window in the Cupola Module.
For the Bell experiment, a pair of entangled photons would be generated on the ground; one would be sent from the ground station to the modified camera aboard the ISS, while the other would be measured locally on the ground for later comparison.
Entangled photons have an intimate connection with each other, even when separated over large distances, which defies the laws of classical physics. A measurement on one of the entangled photons in a pair will determine the outcome of the same measurement on the second photon, no matter how far apart they are.
“According to quantum physics, entanglement is independent of distance. Our proposed Bell-type experiment will show that particles are entangled, over large distances — around 500 km — for the very first time in an experiment,” continued Professor Ursin.
“Our experiments will also enable us to test potential effects gravity may have on quantum entanglement.”
The researchers also propose a quantum key distribution experiment, where a secret cryptographic key is generated using a stream of photons and shared between two parties safe in the knowledge that if an eavesdropper intercepts it, this would be noticed.
Up until now, the furthest a secret key has been sent is just a few hundred kilometres, which would realistically enable communication between just one or two cities.
Research teams from around the world are looking to build quantum satellites that will act as a relay between the two parties, significantly increasing the distance that a secret key could be passed; however, the new research shows that this may be possible by implementing an optical uplink towards the ISS and making a very minor alteration to the camera already on-board.
From Tuesday 9 April, this paper can be downloaded from http://iopscience.iop.org/1367-2630/15/4/043008/article.
Notes to Editors
1. For further information, a full draft of the journal paper or to contact one of the researchers, contact IOP Press Officer, Michael Bishop:
Tel: 0117 930 1032
IOP Publishing Journalist Area
2. The IOP Publishing Journalist Area (http://journalists.iop.org/journalistLogin) gives journalists access to embargoed press releases, advanced copies of papers, supplementary images and videos. In addition to this, a weekly news digest is uploaded into the Journalist Area every Friday, highlighting a selection of newsworthy papers set to be published in the following week.
Login details also give free access to IOPscience, IOP Publishing’s journal platform.
To apply for a free subscription to this service, please email Michael Bishop, IOP Press Officer, email@example.com, with your name, organisation, address and a preferred username.
Quantum optics experiments to the International Space Station ISS: a proposal
3. The published version of the paper “Quantum optics experiments to the International Space Station ISS: a proposal” (T Scheidl et al 2013 New J. Phys. 15 043008) will be freely available online from Tuesday 9 April at http://iopscience.iop.org/1367-2630/15/4/043008/article.
New Journal of Physics
4. New Journal of Physics publishes across the whole of physics, encompassing pure, applied, theoretical and experimental research, as well as interdisciplinary topics where physics forms the central theme. All content is permanently free to read and the journal is funded by an article publication charge.
5. IOP Publishing provides publications through which leading-edge scientific research is distributed worldwide. IOP Publishing is central to the Institute of Physics (IOP), a not-for-profit society. Any financial surplus earned by IOP Publishing goes to support science through the activities of IOP. Beyond our traditional journals programme, we make high-value scientific information easily accessible through an ever-evolving portfolio of community websites, magazines, conference proceedings and a multitude of electronic services. Focused on making the most of new technologies, we’re continually improving our electronic interfaces to make it easier for researchers to find exactly what they need, when they need it, in the format that suits them best. Go to http://ioppublishing.org/
The Institute of Physics
6. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 45,000, working together to advance physics education, research and application. We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.
The German Physical Society
7. The German Physical Society (DPG), with a tradition extending back to 1845, is the largest physical society in the world with more than 59,000 members. The DPG sees itself as the forum and mouthpiece for physics and is a non-profit organisation that does not pursue financial interests. It supports the sharing of ideas and thoughts within the scientific community, fosters physics teaching and would also like to open a window to physics for all those with a healthy curiosity.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.