Analüüs: Teadus & Tehnoloogia – 03 August 2026
Large-Area Twisted Oxide Membranes Advance Twistronics
Topic: Science / Technology,
Sources: ScienceDaily (NC State University / ACS Nano).
Researchers at North Carolina State University have fabricated large-area crystalline sodium niobate membranes with precisely controlled twist angles between layers, then bonded them via annealing to form strong chemical interfaces. This produces moiré superlattices in oxide materials over practical scales that can be transferred to various substrates, moving twistronics beyond fragile van der Waals 2D stacks. Synchrotron X-ray diffraction shows the bonds distort the atomic lattice, creating gradual rotations and phase changes at the interface.
Twistronics traditionally relies on weak interlayer forces in materials like graphene, limiting device scale and stability. Oxides offer stronger bonding and richer electronic, magnetic, and ferroelectric properties, but controlling twist while achieving large areas and crystallinity was previously difficult. The new photolithography-marker and annealing method provides deterministic control over orientation and structure.
Key uncertainties remain in how the lattice distortions and phase shifts fully alter electronic or physical properties; further characterization is required. Scalability to other complex oxides and integration into functional devices also need validation before practical electronics emerge.
Kelvin-Helmholtz Waves Drive Mars Atmospheric Escape
Topic: Space,
Sources: ScienceDaily (Boston University / Science Advances).
Combined data from NASA’s MAVEN and China’s Tianwen-1 reveal that solar wind generates giant Kelvin-Helmholtz waves at the boundary of Mars’ upper atmosphere. These rolling plasma waves form large clouds that bulk-escape atmospheric ions into space, concentrated on the side aligned with the solar wind electric field. The process resembles wind-driven waves on water and provides direct evidence linking the instability to ion loss.
Mars lacks a global magnetic field, leaving its atmosphere exposed to solar wind stripping over billions of years, contributing to the loss of a once thicker, potentially habitable atmosphere and surface water. Prior single-spacecraft data could not simultaneously sample upstream solar wind and escaping ions; dual observations now confirm the mechanism.
The exact contribution of these waves to total atmospheric loss, the conditions favoring their growth, and applicability to unmagnetized exoplanets remain open. MAVEN is nearing end-of-mission, so future data from ESCAPADE and simulations will be needed to quantify rates and evolution.
Hidden Dark Matter Force Suppresses Structure Growth
Topic: Science,
Sources: ScienceDaily (Perimeter Institute / JCAP).
Theoretical models show that an additional long-range attractive “dark force” between dark matter particles causes them to cluster more efficiently yet simultaneously reduces their effective mass as the Universe expands. The mass loss weakens gravitational influence, so the net effect usually slows rather than accelerates the growth of large-scale cosmic structure, contrary to naive expectations.
Observations of expansion history and clustering (including DESI data and cosmic microwave background) show mild tensions with the standard model, prompting exploration of dark-sector interactions invisible to ordinary matter. The force operates only among dark matter particles.
The counterintuitive suppression must be incorporated into broader models invoking dark forces to explain DESI anomalies or structure discrepancies. Upcoming surveys will test which interaction strengths and ranges remain viable; many simple attractive-force scenarios may already be constrained.