Physics Atomic, molecular, and optical physics

Zika virus vaccine targets brain cancer, 120-year quest to farm lobsters, Arctic nightlife bursts with sound, Eating a robot, Molecular orientation is key & New treatment for ALS and dementia. Read all in the latest Editor's Choice.

Understanding electron behavior and surface structure of triphenylene thin film molecules deposited on graphite substrates under light irradiation

Osaka Metropolitan University researchers and their colleagues have successfully detected an ultra-high-energy cosmic ray with an energy level comparable to the most energetic cosmic ray ever observed. The cosmic ray is set to be named after the Japanese sun goddess, Amaterasu. No promising astronomical object has been identified in the direction from which this cosmic ray originated, implying the potential existence of unknown astronomical phenomena and novel physical origins beyond the Standard Model.

A joint research group at Osaka Metropolitan University has succeeded in regulating the flow of single molecules in solution by opening and closing the nanovalve mounted on the nanofluidic device by applying external pressure. The research group fabricated a device with a ribbon-like, thin, soft glass sheet on the top, and at the bottom a hard glass substrate having nanochannels and nanovalve seats. By applying external pressure to the soft glass sheet to open and close the valve, they succeeded in directly manipulating and controlling the flow of individual molecules in solution. They also observed an effect of fluorescence signal amplification when single fluorescent molecules are confined in the tiny nanospace inside the valve. The effect can be ascribed to the nanoconfinement, which suppresses the random motion of the molecules.

Osaka University researchers investigated the physics of laser-driven neutron sources, and found the relationship between the power and the neutrons generated. They were able to decrease the exposure time needed for neutron absorption experiments, which may be employed in biomedical research.

Using a quantum computer, Osaka Metropolitan University researchers utilized quantum logic circuits to directly calculate, in a single calculation, the energy difference between two molecular geometries. The developed method was then applied to execute the molecular geometry optimization of typical molecular systems. On a classical computer, calculations based on the finite difference method require at least two evaluations of the energy for one-dimensional systems, but previous research has shown that a quantum computer can be used to calculate the energy derivatives based on this method in a single calculation. However, quantum circuits relevant to quantum algorithms capable of performing the energy derivative calculations had not been implemented. The research group has successfully created a quantum circuit to calculate the energy derivatives by modifying the quantum circuit used in the previously developed quantum phase difference estimation algorithm.

Researchers from The University of Tokyo Institute of Industrial Science report a machine learning-based model for predicting the bonding properties of materials

Researchers at Osaka Prefecture University have established an approach to identify the orientation of molecules and chemical bonds in crystalline organic-inorganic hybrid thin films deposited on substrates using Fourier transform infrared spectroscopy (FT-IR) and polarized infrared light with a 3D-printed attenuated total reflectance (ATR) unit. This inexpensive method with laboratory-grade equipment quickly reaches the crystal-structure model of even extremely thin films of less than 10 nm.

Diamond is the hardest material in nature. But out of many expectations, it also has great potential as an excellent electronic material. A joint research team led by City University of Hong Kong (CityU) has demonstrated for the first time the large, uniform tensile elastic straining of microfabricated diamond arrays through the nanomechanical approach. Their findings have shown the potential of strained diamonds as prime candidates for advanced functional devices in microelectronics, photonics, and quantum information technologies.

Measuring the temperature of objects at a nanometer-scale has been a long challenge, especially in living biological samples, because of the lack of precise and reliable nanothermometers. An international team of researchers has realized a quantum technology to probe temperature on a nanometer-scale, and have observed a ‘fever’ in tiny nematode worms under pharmacological treatment. This strengthens the connection between quantum sensing and biology and ushers in novel thermal imaging technologies in biomedical research.

Scientists at Tokyo Institute of Technology, RIKEN and Tohoku University have developed a silicone polymer chain that can self-assemble into a 3D periodic structure. They achieved this by using their recently reported self-assembling triptycene molecules to modify the ends of the polymer chains.