The latest news from academia, regulators
research labs and other things of interest
Posted: Sep 16, 2015
Doubt cast on recent study claiming to have unraveled the last mystery of electromagnetism
(Nanowerk News) A group of scientists from ITMO University, Australian National University and Aalto University called into question the results of a study, published by the researchers from Cambridge University in a prestigious scientific journal Physical Review Letters. In the original study (see: "New understanding of electromagnetism could enable antennas on a chip"), the British scientists claimed that they managed to find the missing link in the electromagnetic theory. The findings, according to the scientists, could help decrease the size of antennas in electronic devices manifold, promising a major breakthrough in the field of wireless communications.
The scientific inconsistency of the study was noticed by a group of Russian experts in the field of dielectric nanophotonics from several universities. As it turned out, the paper, which, at first sight, may appear to be a perfectly fine work of scientific inquiry, in fact contains numerous mistakes and inaccuracies that run counter well-known facts from the theory of electrodynamics.
Having carefully studied the original paper, the group prepared an official comment on the paper, in which they challenged the results described by the Cambridge scientists. The comment was recently published by the Physical Review Letters ("Comment on “Electromagnetic Radiation under Explicit Symmetry Breaking”"), the same journal that published the original paper.
The study, conducted by the British scientists, was presented as a breakthrough in the field of wireless communications. According to the official release by the Cambridge University press office, the scientists for the first time found out that the electromagnetic radiation in antennas is caused not merely by the acceleration of electrons, but also by the phenomenon known as symmetry breaking of electromagnetic field. According to the release, from the practical point of view, the discovery could potentially lead to a decrease in the size of antennas to such an extent that they could be integrated inside electronic circuits.
However, according to the authors of the comment, after carefully reading the paper it becomes clear that the results are based on an erroneous interpretation of experiments and surprising lack of understanding of theory.
"Many rather sensational claims, made by our Cambridge colleagues, do not stand to the critical analysis and can be easily refuted simply by looking at the current literature on the topic," says one of the authors of the comment, professor at Aalto University Konstantin Simovsky. "In particular, the paper says that the effectiveness of a resonator is higher when its symmetry is broken or that electromagnetic waves can only be radiated by a non-symmetrical antenna - all these conclusions and absolutely incorrect and can mislead a inexperienced reader."
The situation brings about the issue of the quality of peer review in scientific journals. The authors of the comment express concern with respect to how the review process is carried out in many high-impact journals.
"At the present time, scientists that review papers in scientific journals are picked up from the scientific community. However, their qualifications are not always enough to reasonably evaluate studies that are to be published," says Pavel Belov, head of the Department of Nanophotonics and Metamaterials at ITMO University. "The reviewer's main task now boils down to publishing interesting papers on hot topics, while the true novelty and scientific accuracy of the results are not checked well enough."
The authors of the comment are renowned experts in the field of dielectric nanoantennas for optical and microwave ranges. The group has published numerous research and review papers on the topic of dielectric nanophotonics. Recently, one of the authors of the comment and senior researcher at the Department of Nanophotonics and Metamaterials of ITMO University Alexander Krasnok developed and patented an ultradirectional optical dielectric nanoantenna and a dielectric nanoantenna of Yagi-Uda type.
Dielectric nanoantennas represent a promising alternative to antennas based on metallic nanoparticles. Thanks to the lower losses related to the scattering of radiation in the optical range, dielectric nanoparticles are ideal for effective control and modulation of electromagnetic waves on nanoscale. On top of it, dielectric nanoantennas show other exotic properties that are not inherent in their metallic analogues - it was shown, for instance, that dielectric nanoparticles open possibilities to construct nanoantennas that have simultaneous tunable electric and magnetic response.