An analysis of a record-breaking gravitational-wave detection tests whether general relativity holds under extreme conditions.
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2D discrete time crystals realized on a quantum computer for the first time
Physical systems become inherently more complicated and difficult to produce in a lab as the number of dimensions they exist in increases—even more so in quantum systems. While discrete time crystals (DTCs) had been previously demonstrated in one dimension, two-dimensional DTCs were known to exist only theoretically. But now, a new study, published in Nature Communications, has demonstrated the existence of a DTC in a two-dimensional system using a 144-qubit quantum processor.
Like regular crystalline materials, DTCs exhibit a kind of periodicity. However, the crystalline materials most people are familiar with have a periodically repeating structure in space, while the particles in DTCs exhibit periodic motion over time. They represent a phase of matter that breaks time-translation symmetry under a periodic driving force and cannot experience an equilibrium state.
“Consequently, local observables exhibit oscillations with a period that is a multiple of the driving frequency, persisting indefinitely in perfectly isolated systems. This subharmonic response represents a spontaneous breaking of discrete time-translation symmetry, analogous to the breaking of continuous spatial symmetry in conventional solid-state crystals,” the authors of the new study explain.
MXene nanoscrolls could improve energy storage, biosensors and more
Researchers from Drexel University who discovered a versatile type of two-dimensional conductive nanomaterial called MXene nearly a decade and a half ago, have now reported on a process for producing its one-dimensional cousin: the MXene nanoscroll. The group posits that these materials, which are 100 times thinner than human hair yet more conductive than their two-dimensional counterparts, could be used to improve the performance of energy storage devices, biosensors and wearable technology.
Their finding, published in the journal Advanced Materials, offers a scalable method for producing the nanoscrolls from a MXene precursor with precise control over their shape and chemical structures.
“Two-dimensional morphology is very important in many applications. However, there are applications where 1D morphology is superior,” said Yury Gogotsi, Ph.D., Distinguished University and Bach professor in Drexel’s College of Engineering, who was a corresponding author of the paper.
Light-based nanotechnology offers potential alternative to chemotherapy and radiation
Researchers at NYU Abu Dhabi have developed a new light-based nanotechnology that could improve how certain cancers are detected and treated, offering a more precise and potentially less harmful alternative to chemotherapy, radiation, and surgery. The study advances photothermal therapy, a treatment approach that uses light to generate heat inside tumors and destroy cancer cells.
The research is published in the journal Cell Reports Physical Science.
The NYU Abu Dhabi team designed tiny, biocompatible and biodegradable nanoparticles that carry a dye activated by near-infrared light. When exposed to this light, the particles heat up, damaging tumor tissue while minimizing harm to healthy cells. Near-infrared light was chosen specifically as it penetrates the body to greater depth than visible light, thereby enabling treatment of tumors that are not close to the surface.
A new flexible AI chip for smart wearables is thinner than a human hair
The promise of smart wearables is often talked up, and while there have been some impressive innovations, we are still not seeing their full potential. Among the things holding them back is that the chips that operate them are stiff, brittle, and power-hungry. To overcome these problems, researchers from Tsinghua University and Peking University in China have developed FLEXI, a new family of flexible chips. They are thinner than a human hair, flexible enough to be folded thousands of times, and incorporate AI.
A flexible solution
In a paper published in the journal Nature, the team details the design of their chip and how it can handle complex AI tasks, such as processing data from body sensors to identify health indicators, such as irregular heartbeats, in real time.
Tiny silicon structures compute with heat, achieving 99% accurate matrix multiplication
MIT researchers have designed silicon structures that can perform calculations in an electronic device using excess heat instead of electricity. These tiny structures could someday enable more energy-efficient computation. In this computing method, input data are encoded as a set of temperatures using the waste heat already present in a device.
The flow and distribution of heat through a specially designed material forms the basis of the calculation. Then the output is represented by the power collected at the other end, which is a thermostat at a fixed temperature.
The researchers used these structures to perform matrix vector multiplication with more than 99% accuracy. Matrix multiplication is the fundamental mathematical technique machine-learning models like LLMs utilize to process information and make predictions.
New light-emitting artificial neurons could run AI systems more reliably
Over the past decades, computer scientists have developed increasingly advanced artificial intelligence (AI) systems that perform well on various tasks, including the analysis or generation of images, videos, audio recordings and texts. These systems power various highly performing software, including automated transcription apps, large language model (LLM)-powered conversational agents like ChatGPT, and various other platforms.
Mapping ‘figure 8’ Fermi surfaces to pinpoint future chiral conductors
One of the biggest problems facing modern microelectronics is that computer chips can no longer be made arbitrarily smaller and more efficient. Materials used to date, such as copper, are reaching their limits because their resistivity increases dramatically when they become too small. Chiral materials could provide a solution here. These materials behave like left and right hands: they look almost identical and are mirror images of each other, but cannot be made to match.
“It is assumed that the resistivity in some chiral materials remains constant or even decreases as the chiral material becomes smaller. That is why we are working on using electronic chirality to develop materials for a new generation of microchips that are faster, more energy-efficient and more robust than today’s technologies,” says Professor Niels Schröter from the Institute of Physics at MLU. Until now, however, it has been difficult to produce thin layers of these materials without the left-and right-handed areas canceling each other out in their effects.
This is precisely where the new study, in which the Max Planck Institute for Microstructure Physics in Halle was also involved, comes in. “For the first time, we have found materials that are not yet chiral themselves. However, they have the potential to be converted into electronically chiral materials with only a single-handedness through targeted distortion. These achiral materials can serve as so-called parent materials for engineering chiral conductors with reduced resistivity,” explains Schröter.
Refractive-index microscope measures a sample’s optical properties with pinpoint accuracy
In this way, and almost by chance, researchers at TU Wien developed a novel microscopy technique that allows the refractive index of biological samples to be measured at a resolution far below what conventional light microscopy theory would seem to allow. Their paper is published in the journal ACS Nano.
The trick behind resolution beyond the wavelength of light
What happens if you try to image two molecules whose separation is smaller than the wavelength of light? You will not see two distinct points, but a single blurred spot of light—the images of the two molecules overlap, no matter how precise the microscope is.
Scientists develop high-performance Hg-based crystal for mid-far infrared birefringence
Mid- and far-infrared birefringent crystals are key functional materials for polarization control, laser technologies, and infrared photonics. However, existing materials generally suffer from limited infrared transparency, an intrinsic trade-off between large birefringence and wide transmission windows, and challenges in optical characterization due to restricted crystal dimensions.