Search by tag «Physical Review Letters» 17 results
Physicists Design New Nanoresonators With Giant Nonlinear Response
An international research team has found a way to make frequency conversion of light at the nanoscale a hundred times more efficient. The new method is based on isolated dielectric nanoparticles supporting the so-called bound states in the continuum. Such states appear when radiating fields in the particle suppress each other, so that the electromagnetic energy inside the particle can be trapped. This prediction can be employed for a new generation of tiny frequency conversion devices, nanolasers. The research was published in Physical Review Letters on July 19, 2018 as a cover story.
Physicists Discover Way to Control Transitions Between States of Matter
An international team of physicists has managed for the first time to experimentally observe a transition between two different states of matter: a propagating polariton-soliton and a Bose-Einstein condensate. Furthermore, the researchers developed a theoretical model to explain such transitions and found a way to “switch” between the different states by changing the laser pumping power in the polariton formation process. The results are published in Physical Review Letters.
Physicists Create Crystal Lattice from Polaritons
An international research team has produced an analog of a solid-body crystal lattice from hybrid photon-electron quasiparticles - polaritons. In the resulting polariton lattice, certain particles’ energy does not depend on their speed. At the same time, the lattice’s geometry, particle concentration and polarization properties can still be modified. This opens up new perspectives for study of quantum effects and the use of optical computing. Results of the study were published in Physical Review Letters.
Nanoscale Super-Resonator Extends Light Lifetime
Scientists designed the first subwavelength dielectric resonators for light trapping at nanoscale that appears to be the simple silicon cylinder which is a hundred times thinner than a human hair. Such a structure is capable of trapping light ten times longer than any conventional resonator. Along with a simple shape and small size, this new resonator is a promising basis for the design of powerful nanolasers, biosensors, and various light transmitting devices. The results were published in Physical Review Letters.
ITMO Scientists Prove Skyrmion Laser Manipulation
In recent years the leaders of the global semiconductor industry - companies such as Intel and IBM - have faced inability to accelerate the speed of modern computing systems by increasing the density of microprocessors per unit area. This is caused by fundamental physical limitations. However, it initialized the search for new models and methods of their implementation. Electronics of the future will be based on this research. One of the fields that scientists suggested was spintronics and its subdivision - skyrmionics, which studies exotic magnetic ring formations called skyrmions. They were first obtained in a laboratory in 2010. In the future they may find use in development of more efficient memory chips. Like graphene in the field of nanomaterials, skyrmions can lead the way to go beyond 10-nanometer technological process of chip production. Researchers at ITMO University are also working in this field and have recently managed to demonstrate in theory that properties of skyrmions can be controlled using external laser radiation. The results of this work were published in the Physical Review Letters.
Scientists Achieve Breakthrough in Polariton Laser Technology
An international scientific team has modeled and conducted an experiment in the course of which they have managed to produce an electrically pumped spin-polarized polariton laser. This allows for a reduction in the laser’s energy consumption levels and control over the output polarization. This is achieved thanks to the use of magnetic materials in the device’s contacts: the electrons that come into contact with the laser have a preferred spin direction, which allows for effective spin pumping. Polariton lasers are very promising for the very reason that they do not require high amounts of energy. In addition, they work at room temperatures. Due to this, they can be used in portable electronics, optical computers and communication devices. Results of the experiment have been published in Physical Review Letters.
Researchers Find Way to Enhance Photon Entanglement
Scientists from ITMO University figured out how to design more efficient and compact devices for generating pairs of entangled photons. The research team found that the number of entangled photons increased when the light beam passed through a special nanolattice compiled of metal layers. The effect of entanglement is enhanced by a strong electrical field arising in the lattice. Previously, such experiments could not be analyzed theoretically, which is why the new method opens big opportunities in designing a wide range of quantum devices, for example, elements of optical computers and secure communication systems. The results were published in Physical Review Letters.