Phys.org March 25, 2024 The recent developments in the fabrication and characterization of plasmonic nanostructures have stimulated continuous effects in the search for their potential applications in the photonic fields. In this review article an international team of researchers (India, USA – Vanderbilt University, San Diego State University, Canada) concentrated on the role of plasmonics in photonics, covering recent advances in ultrafast plasmonic materials with focus on all-optical switching. They discussed fundamental phenomena of plasmonic light–matter interaction and plasmon dynamics elaborating on the ultrafast processes unraveled by both experimental and theoretical methods, along with a comprehensive illustration of leveraging ultrafast […]
Author Archives: Hema Viswanath
The world is one step closer to secure quantum communication on a global scale
Phys.org March 25, 2024 An on-demand source of bright entangled photon pairs is needed for quantum key distribution (QKD) and quantum repeaters. The generation of such pairs is based on spontaneous parametric down-conversion (SPDC) in non-linear crystals. However, SPDC pair extraction efficiency is very limited when operating at near-unity fidelity. In principle quantum dots in photonic nanostructures can overcome this limit, but the devices with high entanglement fidelity have low pair extraction efficiency. An international team of researchers (Canada, the Netherlands, Sweden) has demonstrated a measured peak entanglement fidelity of 97.5% ± 0.8% and pair extraction efficiency of 0.65% from an InAsP […]
Top 10 Science and Technology Inventions for the Week of March 22, 2024
01. Cracking the quantum code: Simulations track entangled quarks 02. High-quality microwave signals generated from tiny photonic chip 03. New method enables synthesis of hundreds of new 2D materials 04. Photon-like electrons in a four-dimensional world discovered in a real material 05. Projection mapping leaves the darkness behind 06. Quantum dance to the beat of a drum: Researchers observe how energy of single electron is tuned by surrounding atoms 07. Researchers achieve >99% photoluminescence quantum yield in metal nanoclusters 08. Researchers develop novel ‘super-tetragonal’ sacrificial layer for freestanding oxide membranes 09. Researchers discover new yttrium-hydrogen compounds with implications for high-pressure […]
Backyard insect inspires invisibility devices, next gen tech
Phys.org March 18, 2024 The leafhoppers cover their body surfaces with brochosomes, buckyball-shaped, nanoscopic spheroids with through-holes distributed across their surfaces, representing a class of deployable optical materials that are rare in nature. A team of researchers in the US (University of Pennsylvania, Carnegie Mellon University) investigated the optical form-to-function relationship of brochosomes and demonstrated that the hierarchical geometries of brochosomes are engineered within a narrow size range with through-hole architecture to significantly reduce light reflection. They showed that the diameters of brochosomes are engineered to maximize broadband light scattering, while the secondary through-holes are designed to function as short-wavelength, […]
Cracking the quantum code: Simulations track entangled quarks
Phys.org March 19, 2024 The cascades of particles produced by the fragmentation of supposedly entangled particles emitted from high energy particle collisions should allow testing the real-time response of the QCD vacuum disturbed by the propagation of high-momentum color charges. A team of researchers in the US (Stony Brook University, Brook Haven National Laboratory) developed fully quantum simulations of a massive Schwinger model coupled to external sources representing quark and antiquark jets as produced in e+e− annihilation. They studied the modification of the vacuum chiral condensate by the propagating jets and the quantum entanglement between the fragmenting jets. Their results […]
Enabling a New Paradigm for Flexible, Point of Need Design and Manufacturing
DARPA News March 11, 2024 DARPA’s new Rubble to Rockets (R2) program aims to overcome current limitations to manufacturing in supply chain-denied environments by developing production and design approaches that can accommodate widely variable input materials. Performers will focus on creating an inexpensive, flexible, and robust platform for the production and characterization of raw material for use in structural fabrication. DARPA hypothesizes that the analytical framework would allow for rapid upgrades to incorporate the growing number of new material developments and fabrication methods, thus significantly reducing adoption risk that traditionally take decades to retire. An R2 Industry Day is scheduled […]
Eyes on the impossible: First near-field, subwavelength thermal radiation measurement
Phys.org March 18, 2024 Researchers at Carnegie Mellon University designed a thermal photonic nanodevice for the first measurement of near-field energy transport between two coplanar subwavelength structures over temperature bias up to ∼190 K. Their experimental results demonstrated a 20-fold enhancement in energy transfer beyond blackbody radiation. In contrast with the well-established near-field interactions between two semi-infinite bodies, the subwavelength confinements in nanodevices led to increased polariton scattering and reduction of supporting photonic modes and, therefore, a lower energy flow at a given separation. According to the researchers their work opens new designs for nanodevices, particularly for coplanar near-field energy […]
High-quality microwave signals generated from tiny photonic chip
Nanowerk March 19, 2024 Current implementations of optical frequency division (OFD) require multiple lasers, with space- and energy-consuming optical stabilization and electronic feedback components, resulting in device footprints incompatible with integration into a compact and robust photonic platform. A team of researchers in the US (industry, Columbia University) demonstrated all-optical OFD on a photonic chip by synchronizing two distinct dynamical states of Kerr microresonators pumped by a single continuous-wave laser. The inherent stability of the terahertz beat frequency was transferred to a microwave frequency of a Kerr soliton comb, and synchronized via a coupling waveguide without the need for electronic […]
Holographic message encoded in simple plastic
Phys.org March 18, 2024 Researchers in Austria produced a sub-terahertz holographic image of a two-dimensional 576-bit data code using a diffractive phase-plate element. The phase plate was designed to encode a focused image of the data code into a phase modulation profile. The complex phase plate structure is fabricated from polylactic acid using fused deposition modeling, a common three-dimensional-printing technique. The simplified optical setup, consisted of a 0.14 THz diverging source, the holographic phase plate, and a scanning detector, without the need for additional optical elements. The information stored in the data code was an example of a cryptographic private […]
New method enables synthesis of hundreds of new 2D materials
Phys.org March 14, 2024 MXenes are a family of 2D materials typically formed by etching the A element from a parent MAX phase. Computational screening for other 3D precursors suitable for such exfoliation is challenging because of the intricate chemical processes involved. Researchers in Sweden proposed a theoretical approach for predicting 2D materials formed through chemical exfoliation under acidic conditions by identifying 3D materials amenable for selective etching. From a dataset of 66,643 3D materials, they identified 119 potentially exfoliable candidates, within several materials families. To corroborate the method, they chose a material distinctly different from MAX phases, in terms […]