Science Daily February 15, 2024 Arrays of Rydberg atoms are suitable to study quantum phase transitions in one dimension. Theoretically predicted chiral transition out of period-four phase is still pending experimental verification mainly due to extremely short interval over which this transition is realized in a single-component Rydberg array. Researchers in the Netherlands showed that multicomponent Rydberg arrays with extra experimentally tunable parameters provided a mechanism to manipulate quantum critical properties without breaking translation symmetry explicitly. They considered an effective blockade model of two component Rydberg atoms. Weak and strong components obeyed nearest- and next-nearest-neighbor blockades correspondingly. When laser detuning […]
A new record for atom-based quantum computers: 1,000 atomic qubits and rising
Phys.org February 15, 2024 Researchers in Germany designed a large-scale quantum-processing architecture surpassing the tier of 1000 atomic qubits. By tiling multiple microlens-generated tweezer arrays, each operated by an independent laser source, they eliminated laser-power limitations in the number of allocatable qubits. With two separate arrays, they implemented combined 2D configurations of 3000 qubit sites with a mean number of 1167(46) single-atom quantum systems. The transfer of atoms between the two arrays effectively. Supercharging one array designated as the quantum processing unit with atoms from the secondary array significantly increased the number of qubits and the initial filling fraction. They […]
Physicists develop new solar cell design for better efficiency
Phys.org February 20, 2024 Photovoltaics offers a large potential for the supply of clean and renewable energy. Silicon solar cells used for this purpose have efficiency limits. One reason for this is that some of the energy from short-wave radiation is not converted into electricity, but into unwanted heat. Through computer simulation researchers in Germany showed that to increase the efficiency, the silicon solar cell could be provided with an organic layer, for example made from the semiconductor tetracene. Short-wave light is absorbed in this layer and converted into high-energy excitons. These excitons decay in the tetracene into two low-energy […]
Quantum dark states lead to an advantage in noise reduction
Phys.org February 19, 2024 Researchers at the University of Colorado described a method to create and store scalable and long-lived entangled spin-squeezed states within a manifold of many-body cavity dark states using collective emission of light from multilevel atoms inside an optical cavity. They showed that the system could be tuned to generate squeezing in a dark state where it will be immune to super radiance. More generically that squeezing could be generated using a combination of super radiance and coherent driving in a bright state, and subsequently transferred via single-particle rotations to a dark state where squeezing could be […]
Researchers achieve breakthrough in silicon-compatible magnetic whirls
Phys.org February 20, 2024 Antiferromagnets hosting real-space topological textures are promising platforms to model fundamental ultrafast phenomena and explore spintronics. However, as they are epitaxially fabricated on specific symmetry-matched substrates, preserving their intrinsic magneto-crystalline order, curtails their integration with dissimilar supports, restricting the scope of fundamental and applied investigations. An international team of researchers (UK, Switzerland, Singapore) circumvented this limitation by designing detachable crystalline antiferromagnetic nanomembranes of α-Fe2O3. They showed that flat nanomembranes host a spin-reorientation transition and rich topological phenomenology. They demonstrated the reconfiguration of antiferromagnetic states across three-dimensional membrane folds resulting from flexure-induced strains. They combined these developments […]
Researchers develop world’s most efficient quantum dot solar cell
Nanowerk February 21, 2024 Research has predominantly focused on inorganic cation perovskite-based colloidal quantum dots (PQDs) even though organic cation PQDs have more favorable bandgaps. Researchers in South Korea developed solar cells using narrow bandgap organic cation based PQDs and demonstrated substantially higher efficiency compared with their inorganic counterparts. They employed an alkyl ammonium iodide-based ligand exchange strategy, which proved to be substantially more efficient in replacing the long-chain oleyl ligands than conventional methyl acetate-based ligand exchange while stabilizing the α phase of organic PQDs in ambient conditions. They showed a solar cell with the organic cation PQDs with high […]
‘Scientists’ warning’ on climate and technology
Science Daily February 15, 2024 Current technological systems are exacerbating climate change and the wholesale conversion of the Earth’s ecosystems. Adopting new technologies, such as clean energy technologies and artificial intelligence, may be necessary for addressing these crises. Such transformation is not without risks, but it may help set human civilizations on a path to a sustainable future. An international team of researchers (USA – UC Irvine, University of Kansas, Oregon State University, MIT, New Zealand) provided an integrative review of approaches that scholars and practitioners have taken in enacting technological change, and provide a framework for how these approaches […]
Surface to Air Missiles Are Too Slow and Weak To Catch SpaceX Starship
Next Big Future February 19, 2024 A SpaceX Starship will be much harder to shootdown than an ICBM. It is like an ICBM with massive course change capabilities. A SAM-5 surface to air missile is a larger missile with a top speed of Mach 4 and reaches an altitude up to 19 miles. Passenger airplanes have a cruising altitude of 33,000 to 40,000 feet (6-8 miles). The Russian S-200 SAM has a maximum altitude of 180,000 feet (55 km or 34 miles). It is generally expected that it will take four interceptors to have high probability of taking out an […]
US Air Force readies to award collaborative combat aircraft deals
Defense News February 13. 2024 Air Force plans to award contracts for the next round of Collaborative Combat Aircraft (CCAs) — drones loaded with autonomous software that would fly themselves into battle alongside crewed fighters — in fiscal 2025. On the first increment of CCAs, the Air Force has contracts with five companies: Lockheed Martin, Boeing, Northrop Grumman, General Atomics and Anduril. The Air Force plans to field several different types of CCAs, with different capabilities and levels of survivability, to carry out a wide range of missions including strikes, surveillance, jamming, and serving as decoys to draw enemy fire. […]
With just a little electricity, researchers boost common catalytic reactions
Science Daily February 15, 2024 Electric fields play a key role in enzymatic catalysis and can enhance reaction rates by 100,000-fold, but the same rate enhancements have yet to be achieved in thermochemical heterogeneous catalysis. Researchers at MIT probed the influence of catalyst potential and interfacial electric fields on heterogeneous Brønsted acid catalysis. They found that variations in applied potential of ~380 mV led to a 100,000-fold rate enhancement for 1-methylcyclopentanol dehydration, which was catalyzed by carbon-supported phosphotungstic acid. Mechanistic studies supported a model in which the interfacial electrostatic potential drop drove quasi-equilibrated proton transfer to the adsorbed substrate prior […]