Phys.org December 10, 2024 Qubit connectivity on a planar surface is typically restricted to only a few neighboring qubits. Overcoming the complex multilayer packaging, external cabling, and fidelity limitations, a team of researchers in the US (University of Chicago, Argonne National Laboratory) proposed and developed a high-speed on-chip quantum processor that supported reconfigurable all-to-all coupling with a large on-off ratio. They implemented the design in a four-node quantum processor, built with a modular design comprising a wiring substrate coupled to two separate qubit-bearing substrates, each including two single-qubit nodes. Using the device they demonstrated reconfigurable controlled- gates across all qubit […]
Room-temperature nanodevice that generates structured light shows promise for secure communication and advanced optics
Phys.org December 10, 2024 An international team of researchers (Israel, USA – UT Austin, Los Alamos National Laboratory, Germany, Italy) harnessed the potential of radially polarized photons for classical and quantum communication applications to demonstrate an on-chip, room-temperature device, which generated highly directional radially polarized photons at very high rates. The photons were emitted from a giant CdSe/CdS colloidal quantum dot (gQD) accurately positioned at the tip of a metal nanocone centered inside a hybrid metal-dielectric bullseye antenna. They showed that the emitted photons could have a very high degree of radial polarization, based on a quantitative metric. According to […]
Scientists develop cost-effective lasers for extended short-wave infrared applications
Phys.org December 10, 2024 Currently, the spectral coverage of solution-processed lasers extends from visible up to telecom wavelengths in the short-wave infrared. Using lead sulphide based colloidal quantum dots researchers in Spain demonstrated the optical gain in the extended SWIR from 1600 nm to 2500 nm which has many applications such as in LIDAR, biological imaging and environmental monitoring. Using the carbon quantum dots (CQDs) in distributed feedback laser cavities, lasing with emission was tuned between 2150 nm and 2500 nm is reported. Due to the increased absorption cross-section of larger CQDs, the optical gain threshold was reduced by a […]
Scientists reveal superconductivity secrets of an iron-based material
Phys.org December 5, 2024 Although this high Tc is thought to be associated with electron–phonon coupling (EPC), the microscopic coupling mechanism and its role in the superconductivity remain elusive. An international team of researchers (USA – UC Irvine, Princeton University, China, Sweden) atomically resolved the phonons at the FeSe/STO interface and uncovered new optical phonon modes, coupling strongly with electrons, in the energy range of 75–99 meV. These modes were characterized by out-of-plane vibrations of oxygen atoms in the interfacial double-TiOx layer and the apical oxygens in STO. Their results demonstrated that the EPC strength and superconducting gap of 1 uc FeSe/STO […]
Space-time crystals, an important step toward new optical materials
Nanowerk December 8, 2024 Photonic time crystals consist of materials with uniform composition in space, but properties that vary periodically over time which allows the modulation of the spectral composition of light, and amplification as needed. It is on high demand for current, and possibly also future materials platforms because their small modulation strength. An international team of researchers (Germany, Finland) demonstrated that by introducing temporal variations in a resonant material, the momentum bandgap could be drastically expanded with modulation strengths with known low-loss materials and realistic laser pump powers. The resonance could emerge from an intrinsic material resonance or […]
Straining a material’s atomic arrangement may make for cleaner, smarter devices
Phys.org December 5, 2024 Strong coupling between polarization (P) and strain (ɛ) in ferroelectric complex oxides offers unique opportunities to dramatically tune their properties. An international team of researchers (USA – Pennsylvania State University, Cornell University, Stanford University, University of Nebraska, Argonne National Laboratory, Belgium, Germany) demonstrated strain tuning of ferroelectricity in epitaxial potassium niobate (KNbO3) thin films grown by sub-oxide molecular beam epitaxy. While bulk KNbO3 exhibited three ferroelectric transitions and a Curie temperature (Tc) of ≈676 K, phase-field modeling predicted that a biaxial strain pushes its Tc > 975 K, its decomposition temperature in air, and for −1.4% […]
Tuning skyrmion helicity for racetrack memory and quantum computing applications
Phys.org December 11, 2024 An international team of researchers (USA – Texas Tech University, China, Saudi Arabia, Sweden Japan) applied electric current pulses to a magnetic multilayer stripe composed of [Pt/Co]3/Ru/[Co/Pt]3 and observed skyrmion motion opposite to the current direction. Upon continuous pulsing, a reversal in the particles’ motion direction was noted. Experimental and micromagnetic simulation analyses revealed that skyrmions in the upper and lower ferromagnetic layers of the multilayer system exhibited different helicities, forming a hybrid synthetic ferromagnetic skyrmion. The helicity switch of the hybrid structure accounted for the motion reversal. According to the researchers their study introduces innovative […]
What do we know about the economics of AI?
MIT News December 6, 2024 Researchers at MIT evaluated claims about the large macroeconomic implications of new advances in AI. So long as AI’s microeconomic effects are driven by cost savings/productivity improvements at the task level, its macroeconomic consequences will be given by Gross Domestic Product (GDP) and aggregate productivity gains can be estimated by what fraction of tasks are impacted and average task-level cost savings. Predicted TFP gains over the next 10 years could be modest. They showed theoretically that even when AI improves the productivity of low-skill workers in certain tasks it may increase rather than reduce inequality. Empirically, […]
Top 10 Science and Technology Inventions for the Week of January 6, 2025
01. Breakthrough anti-counterfeiting tech creates hidden security features in materials 02. Light and symmetry study may offer opportunities for anti-counterfeiting 03. Researchers demonstrate self-assembling electronics 04. Self-heating flexible electronics lower manufacturing temperature requirements 05. Researchers use laser beams to pioneer new quantum computing breakthrough 06. 3D-printed particles propel themselves across the surface of a fluid 07. Cooperative motion by atoms protects glass from fracturing 08. Microscopy at the tip of a hair-thin optical fiber: New approach pre-shapes light for unprecedented control 09. AI fact checks can increase belief in false headlines, study finds 10. New spin quantum battery can be […]
3D-printed particles propel themselves across the surface of a fluid
Phys.org December 1, 2024 Marangoni surfers are simple, cost-effective tabletop experiments that, despite their simplicity, exhibit rich dynamics and collective behaviors driven by physicochemical mechanisms, hydrodynamic interactions, and inertial motion. An international team of researchers (the Netherlands, USA – Harvard University) designed, developed and manufactured self-propelled particles to move on the air-water interface. They had tunable motility, and surface tension-mediated forces-controlled particle-particle interactions. Rapid prototyping through 3D printing facilitated the exploration of a wide design space, enabled precise control over particle shape and function. They investigated self-assembly in the system and highlighted its potential for modular designs where mechanically linked […]