Science Daily June 1, 2022 Anderson localization predicts that transport in one-dimensional uncorrelated disordered systems comes to a complete halt, experiencing no transport whatsoever. However, a disordered physical system is always correlated because it must have a finite spectrum. Localization is dominant only for wave packets whose spectral extent resides within the region of the wave number span of the disorder. An international team of researchers (Israel, Germany, Spain) has experimentally shown that Anderson localization can occur and even be dominant for wave packets residing entirely outside the spectral extent of the disorder. The team studied the evolution of wave […]
Category Archives: Light- matter interaction
Physicists discover light-induced mechanism for controlling ferroelectric polarization
Phys.org May 10, 2022 Ferroelectric materials exhibit ferroelectricity and the ability to polarize spontaneously. Typically, researchers can manipulate and reverse the polarization by the application of an external electric field. Ultrafast interactions between light and matter are another promising route for controlling ferroelectric polarization, but until now researchers have struggled to achieve a light-induced, deterministic control of such polarization. An international team of researchers (USA – University of Arkansas, France, Luxembourg) discovered a so-called “squeezing effect” in ferroelectric materials subject to femtosecond laser pulses. These pulses destroyed the polarization component that is parallel to the field’s direction and created polarization […]
High-Energy Interactions Between Light and Matter Described by Advanced New Mathematical Model
SciTech Daily March 15, 2022 High-harmonic generation has several applications, way to create table-top sources of extreme ultraviolet or x-ray light using lasers, and produce ultrashort light pulses, which are useful for imaging extremely rapid processes such as those that occur in atoms. But high-harmonic generation is inherently difficult to model mathematically, and understand fully. An international team of researchers (Japan, USA – University of Chicago) has developed an analytical approach to high-harmonic generation in the non-perturbative regime using mathematical techniques that had not previously been applied to high-harmonic generation. Their approach revealed the microscopic mechanism that converts incoming intense […]
Quantum information: Light from rare-earth molecules
Nanowerk March 11, 2022 Rare-earth ions (REIs) are promising solid-state systems for building light–matter interfaces at the quantum level. However, few crystalline materials have shown an environment quiet enough to fully exploit REI properties. Molecular systems can provide such capability but generally lack spin states and they show broad optical lines that severely limit optical-to-spin coherent interfacing. An international team of researchers (France, Germany) found that europium molecular crystals exhibit linewidths in the tens of kilohertz range, orders of magnitude narrower than those of other molecular systems. They harnessed this property to demonstrate efficient optical spin initialization, coherent storage of […]
Ultra-thin crystals as light sources in lasers
Nanowerk November 8, 2021 Previously an international team of researchers (Germany, Russia, USA – Arizona State University, Japan) reported that a layer of the semiconductor material molybdenum diselenide generated laser light at cryogenic temperatures. Now they created the same effect at room temperature in exciton-polaritons. If sufficient exciton-polaritons are generated, they merge into a macroscopic quantum state. A sudden increase in light emission from the sample indicates that this transformation has taken place. The resulting radiation has only a single wavelength and displays coherence. To demonstrate the effect, they placed thin layers of tungsten diselenide between special mirrors. By studying the […]
A highly simplified way to predict quantum light-matter interactions
Phys.org October 13, 2021 Calculating quantum light-matter takes enormous amounts of time and computing power—it also becomes very cumbersome. An international team of researchers (Germany, Sweden, Austria) has found a simple way to circumvent this problem by reshaping the equation so that the material part itself accounts for the quantum mechanical uncertainty of the light, far fewer additional photons are needed to describe the combined system of quantum light and matter. The new approach can capture most features of this extreme limit without the need to consider any photon at all. Adding just a few photons is enough to provide […]
Optically generated quantum fluids of light reveal exotic matter-wave states in condensed matter physics
Phys.org September 30, 2021 An international team of researchers (Russia, UK) used all-optical methods to create an artificial lattice whose nodes house polaritons called Lieb lattice, which usually does not occur in nature. Programmable spatial light modulator was used to shape a laser beam into a lattice inside the cavity. The generated polaritons both increased in number and became more energetic where the laser field was most intense and forming condensates at high enough laser power. The high-energy polariton waves escaped the condensates scattered and diffracted across the lattice. When the lattice constant was decreased, the condensates underwent a phase transition […]
The nanophotonics orchestra presents: Twisting to the light of nanoparticles
Science Daily September 20, 2021 In 3D isotropic liquids, optical third-harmonic generation is forbidden, with circularly polarized light (CPL). Yet the associated nonlinear susceptibility directly influences the optical properties at the fundamental frequency by intensity dependence. An international team of researchers (UK, Germany) has revealed the hidden third-harmonic optical properties upon circularly polarized light (CPL) by demonstrating a new effect, in hyper-Rayleigh scattering. The intensity of light scattered at the third-harmonic frequency of the CPL incident light depends on the chirality of the scatterers. It is referred to as third harmonic (hyper) Rayleigh scattering optical activity (THRS OA) and was […]
Nanostructures enable record high-harmonic generation
Phys.org July 21, 2021 Resonantly enhanced High harmonic generation (HHG) from hot spots in nanostructures is an attractive route to overcoming the well-known limitations of gases and bulk solids. An international team of researchers (USA – Cornell University, Ohio State University, Singapore) demonstrated an ultra-thin resonant gallium phosphide platform for highly efficient HHG driven by intense mid-infrared laser pulses. The gallium-phosphide material permits harmonics of all orders without reabsorbing them, and the specialized structure can interact with the laser pulse’s entire light spectrum. The enhanced conversion efficiency facilitates single-shot measurements that avoid material damage and pave the way to study […]
Scientists produce a quantum state that is part light and part matter
Nanowerk December 7, 2020 An international team of researchers (USA – University of Minnesota, University of Maryland, University of Colorado, Vanderbilt University, Spain) developed a unique process in which they achieved “ultra-strong coupling” between infrared light (photons) and matter (atomic vibrations) by trapping light in tiny, annular holes in a thin layer of gold. These nanocavities, like a highly scaled-down version of the coaxial cables that are used to send electrical signals. With this new process to engineer nanometer-sized version of coaxial cables, they are pushing the frontiers of ultra-strong coupling, which means they are discovering new quantum states where […]