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 […]
Our DNA is becoming the world’s tiniest hard drive
Phys.org October 4, 2021 The multipart architecture of current DNA-based recording techniques renders them inherently slow and incapable of recording fluctuating signals with subhour frequencies. To address this limitation, a team of researchers in the US (Northwestern University, Johns Hopkins University, Columbia University, MIT, University of Pennsylvania) developed a simplified system employing a single enzyme, terminal deoxynucleotidyl transferase (TdT), to transduce environmental signals into DNA. TdT adds nucleotides to the 3′-ends of single-stranded DNA (ssDNA) in a template-independent manner, selecting bases according to inherent preferences and environmental conditions. By characterizing TdT nucleotide selectivity under different conditions, they showed that TdT […]
Researchers Discover Evidence of a Major Coronavirus Epidemic 20,000 Years Ago
SciTech Daily October 4, 2021 An international team of researchers (Australia, USA – University of Arizona, UC San Francisco) applied evolutionary analyses to human genomic datasets to recover selection events involving tens of human genes that interact with coronaviruses that likely started more than 20,000 years ago. Multiple lines of functional evidence support an ancient viral selective pressure, and East Asia is the geographical origin of several modern coronavirus epidemics. An arms race with an ancient coronavirus, or with a different virus that happened to use similar interactions as coronaviruses with human hosts, may thus have taken place in ancestral East […]
Researchers reach quantum networking milestone in real-world environment
Phys.org October 6, 2021 A team of researchers in the US (Oak Ridge National Laboratory, Stanford University, Purdue University) implemented flex-grid entanglement distribution in a deployed network connecting nodes in three distinct campus buildings time synchronizing via the Global Positioning System. They quantify the quality of the distributed polarization entanglement via log-negativity, which offers a generic metric of link performance in entangled bits per second. After demonstrating successful entanglement distribution for two allocations of their eight dynamically reconfigurable channels, they realized the first deployed fiber network demonstration of remote state preparation (RSP), a fundamental quantum communications protocol with utility for […]
Skyrmion research: Braids of nanovortices discovered
Phys.org October 6, 2021 Braided structures are commonly seen in nature. An international team of researchers (Germany, Sweden, China) has discovered that such structures exist on the nanoscale in alloys of iron and the metalloid germanium. These nanostrings are each made up of several skyrmions that are twisted together to a greater or lesser extent, rather like the strands of a rope. Each skyrmion itself consists of magnetic moments that point in different directions and together take the form of an elongated tiny vortex. The length of the magnetic structures is limited only by the thickness of the sample. Earlier […]
Smuggling light through opaque materials
Nanowerk October 5, 2021 Chalcogenide glasses have long been constrained to the near- and mid-infrared with respect to their applications in photonics because they strongly absorb wavelengths of light in the visible and ultraviolet parts of electromagnetic spectrum. An international team of researchers (USA – Duke University, US Naval Research Laboratory, industry, university of Pennsylvania, Aviation and Missile Center, Aviation and Missile Center, US Army, Italy) has experimentally demonstrated and reported near-infrared to ultraviolet frequency conversion in an As2S3-based metasurface, enabled by a phase locking mechanism between the pump and the inhomogeneous portion of the third harmonic signal. Due to […]
Trapping light with disorder
Phys.org October 5, 2021 A random laser has many degrees of freedom that are not available in conventional cavity lasers. Based on this discovery, an international team of researchers (Israel, France) showed that laser emission can be simply controlled by shaping the pump profile that provides the gain inside the scattering medium. This is done optically with total flexibility. They found that selective excitation significantly reduces the lasing threshold, while lasing efficiency is greatly improved. Their spatial locations are critical to boost laser power efficiency. By efficiently suppressing the spatial hole burning effect, they could turn on the optimally outcoupled random […]
Top 10 Science and Technology Inventions for the Week of October 1, 2021
01. Researchers integrate optical devices made of multiple materials onto single chip 02. Scientists create material that can both move and block heat 03. Tiny lasers acting together as one: Topological vertical cavity laser arrays 04. Twisted layers of MoS2 enable the engineering of novel states of matter 05. Ultrathin quantum dot LED that can be folded freely as paper 06. Unbreakable glass inspired by seashells 07. Implementing a 46-node quantum metropolitan area network 08. A 15-user quantum secure direct communication network 09. Disrupting Exploitable Patterns in Software to Make Systems Safer 10. Flexible, stretchable battery capable of moving smoothly […]
A 15-user quantum secure direct communication network
Phys.org September 23, 2021 Researchers in China have created a quantum direct secure communication (QSDC) network based on time–energy entanglement and sum-frequency generation with15 users. They found that fidelity of the entangled state shared by any two users is >97%, when any two users are performing QSDC over 40 km of optical fiber, the fidelity of the entangled state shared by them is still >95%, and the rate of information transmission could be maintained above 1 Kbp/s. The work demonstrates the feasibility of a proposed QSDC network for satellite-based long-distance and global QSDC in the future…read more. Open Access TECHNICAL ARTICLE
‘Back to basics’ approach helps unravel new phase of matter
Science Daily September 27, 2021 It was thought that the properties of prethermal discrete time crystals (DTCs) were reliant on quantum physics. An international team of researchers (UK, Germany) found that a simpler approach, based on classical physics can be used to understand these mysterious phenomena. Using a computer simulation they studied many interacting spins under the action of a periodic magnetic field using classical Hamiltonian dynamics. The resulting dynamics showed in a neat and clear way the properties of prethermal DTCs: for a long time, the magnetization of the system oscillates with a period larger than that of the […]