Proceedings

EPJ D - Disentangling information from photons

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Study describes greater chances of accessing more reliable information on applications in quantum computing and cryptography.

Theoretical physicist Filippo Miatto and colleagues from the University of Strathclyde, Glasgow, UK, have found a new method of reliably assessing the information contained in photon pairs used for applications in cryptography and quantum computing. The findings, published in EPJD, are so robust that they enable access to the information even when the measurements on photon pairs are imperfect.

The authors focused on photon pairs described as being in a state of quantum entanglement: i.e., made up of many superimposed pairs of states. This means that these photon pairs are intimately linked by common physical characteristics such as a spatial property called orbital angular momentum, which can display a different value for each superimposed state.

Miatto and his colleagues relied on a tool capable of decomposing the photon pairs’ superimposed states onto the multiple dimensions of a Hilbert space, which is a virtual space described by mathematical equations. This approach allowed them to understand the level of the photon pairs’ entanglement.

The authors showed that the higher the degree of entanglement, the more accessible the information that photon pairs carry. This means that generating entangled photon pairs with a sufficiently high dimension—that is with a high enough number of decomposed photon states that can be measured—could help reveal their information with great certainty.

As a result, even an imperfect measurement of photons’ physical characteristics does not affect the amount of information that can be gained, as long as the level of entanglement was initially strong. These findings could lead to quantum information applications with greater resilience to errors and a higher information density coding per photon pair. They could also lead to cryptography applications where fewer photons carry more information about complex quantum encryption keys.

Cartesian and polar Schmidt bases for down-converted photons.F.M. Miatto, T. Brougham, A.M. Yao, Eur. Phys. J. D (2012) 66: 183, DOI 10.1140/epjd/e2012-30063-y.

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
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On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

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