Little more than a system of two energy levels could be used to control a single particle of light
Modern electronics is built upon the control of electric charges through an electric field. Computing based on photons rather than electrons, on the other hand, promises significantly faster computation and information processing. An international team of researchers has now developed a theoretical system that would allow single photons to be controlled reliably. “The system we propose can be used as a quantum switch to control the transport of single photons,” says team member Franco Nori from the Advanced Science Institute, Wako, and The University of Michigan, USA.
In contrast to electrons, exercising control over photons is rather difficult to achieve, because light travels at high speeds and hardly interacts with matter. This has hampered the realization of schemes such as all-optical computing. The use of resonators, however, offers a solution to better control the way light propagates. Resonators are small cavities, bound by mirrors at both ends that bounce light back and only occasionally let light out.
As reported in the journal Physical Review Letters (1), the researchers studied a chain of resonators coupled together so that photons propagate along this line. A system with two energy levels was placed in the center of this coupled-resonator waveguide. To facilitate the interaction between light and the two-level system the separation of the two energy levels is close to the photon energy.
When there is a perfect match between the photon energy and the separation of energy levels, the two-level system interacts with the photon; physics then dictates that the photon will be reflected. However, when the energies of the photon and the two-level system do not match, the photon will be transmitted towards the other end of the waveguide.
“Such a two-level system with adjustable energy levels could be used as a switch that controls the propagation of a single photon in the same way a transistor controls the transport of electrons,“ says team member C. P. Sun from The Chinese Academy of Sciences, Beijing.
To realize this two-level system the researchers suggest using so-called superconducting qubits, used in connection with superconducting resonators, which have been demonstrated already, as the waveguides. The separation of the qubit energy levels can be easily controlled and could even be done with another single photon. The researchers have demonstrated theoretically that, with the right choice of system parameters, switching can be easily achieved. “We believe such a system is well within reach of current technology,” says RIKEN’s Lan Zhou.
1. Zhou, L., Gong, Z. R., Liu, Y.-X., Sun, C. P. & Nori, F. Controllable Scattering of a Single Photon inside a One-Dimensional Resonator Waveguide. Physical Review Letters 101, 100501 (2008).
The corresponding author for this highlight is based at the RIKEN Digital Materials Team
Timing a space laser with a NASA-style stopwatch
28.03.2017 | NASA/Goddard Space Flight Center
Cutting edge research for the industries of tomorrow – DFKI and NICT expand cooperation
21.03.2017 | Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Physics and Astronomy
28.03.2017 | Health and Medicine
28.03.2017 | Life Sciences