Phys.org July 3, 2024 When the tilting angles are arbitrary, the grain boundaries in atomically thin van der Waals materials form inhomogeneous sublattices, giving rise to local electronic states that are not controlled. An international team of researchers (Korea, USA – Harvard University) has reported on epitaxial realizations of deterministic MoS2 mirror twin boundaries (MTBs) at which two adjoining crystals are reflection mirroring by an exactly 60° rotation by position-controlled epitaxy. They showed that these epitaxial MTBs were one-dimensionally metallic to a circuit length scale. They incorporated the epitaxial MTBs as a 1D gate to build integrated two-dimensional field-effect transistors […]
Scientists probe chilling behavior of promising solid-state cooling material
Phys.org July 1. 2024 A nickel-cobalt-manganese-indium magnetic shape-memory alloy, can be deformed and then returned to its original shape by driving it through a phase transition. When subjected to a magnetic field, the material undergoes a magnetic and structural phase transition, during which it absorbs and releases heat. An international team of researchers (USA – Oak Ridge National Laboratory, Texas A&M University, NIST, Russia) showed that localized magnon-phonon hybrid modes, which are inherently spread across reciprocal space, act as a bridge between phonons and magnons and result in substantial magnetic field–induced shifts in the phonons and alter phase stability. They […]
Self-assembling, highly conductive sensors could improve wearable devices
Science Daily July 1, 2024 Soft and stretchable conductors with high electrical conductivity and tissue-like mechanical properties are crucial for both on-skin and implantable electronic devices. Liquid metal-based conductors hold great promise due to their metallic conductivity and minimal stiffness. However, the surface oxidation of liquid metal particles in polymeric matrices poses a challenge in forming a continuous pathway for highly conductive elastic composites. Researchers at the Pennsylvania State University reported a printable composite material based on liquid metal and conducting polymer that undergoes a self-assembly process, achieving high conductivity in the bottom surface while maintaining an insulated top surface, […]
Simple new process stores carbon dioxide in concrete without compromising strength
Phys.org June 26, 2024 The current concrete carbonation approaches are hindered by low CO2 capture efficiency and high energy consumption, often resulting in weakened concrete. An international team of researchers (USA – Northwestern University, Switzerland) experimentally explored a carbonation approach that resorts to injecting CO2 into a cement suspension subsequently used to manufacture concrete, turning the carbonation reaction into an aqueous ionic reaction with a very fast kinetics compared to traditional diffusion-controlled approaches. This approach achieved a CO2 sequestration efficiency of up to 45% and maintained an uncompromised concrete strength. The study showed that the CO2 injection rate influenced the […]
Survey finds public perception of scientists’ credibility has slipped
Phys.org June 27, 2024 New analyses from researchers at the University of Pennsylvania perceptions of scientists’ credibility—measured as their competence, trustworthiness, and the extent to which they are perceived to share an individual’s values—remain high, but their perceived competence and trustworthiness eroded somewhat between 2023 and 2024. The research also found that public perceptions of scientists working in artificial intelligence (AI) differ from those of scientists. The five factors in FASS (Factors Assessing Science’s Self-Presentation model) are whether science and scientists are perceived to be credible and prudent, perceived to overcome bias, correct error (self-correcting), and their work benefits people […]
Understanding quantum states: New research shows importance of precise topography in solid neon qubits
Phys.org June 26, 2024 Single electrons trapped on solid-neon surfaces, which have long coherence times, are promising platform for charge qubits. The actual quantum states of the trapped electrons have not been understood. A team of researchers in the USA (National High Magnetic Field Laboratory (Florida), Florida State University, University of Florida, FAMU-FSU College of Engineering) examined the electron’s interactions with neon surface topography and by evaluating the surface charges induced by the electron, they demonstrated its strong perpendicular binding to the neon surface. They revealed that surface bumps could bind an electron, forming unique quantum ring states that aligned […]
Top 10 Science and Technology Inventions for the Week of June 28, 2024
01. Researchers discover new flat electronic bands, paving way for advanced quantum materials 02. Researchers move floating objects with soundwaves 03. Controlling electronics with light: the magnetite breakthrough 04. New photonic chip spawns nested topological frequency comb 05. An optical lens that senses gas 06. Physicists propose time crystal-based circuit board to reduce quantum computing errors 07. Stacking three layers of graphene with a twist speeds up electrochemical reactions 08. Researchers create new class of materials called ‘glassy gels’ 09. Researchers develop tunable anti-counterfeiting material 10. Space radiation can damage satellites—next-generation material could self-heal when exposed to cosmic rays And […]
Controlling electronics with light: the magnetite breakthrough
Nanowerk June 21, 2024 Symmetry breaking across phase transitions often causes changes in selection rules and emergence of optical modes which can be detected via spectroscopic techniques or generated coherently in pump-probe experiments. An international team of researchers (Switzerland, Poland, Czech Republic, Italy) demonstrated that in magnetite (Fe3O4) light excitation coupled to the critical fluctuations of the charge order and coherently generated structural modes of the ordered phase above the critical temperature of the Verwey transition. According to the researchers their methodology represents an effective tool to study the real-time dynamics of critical fluctuations across phase transitions… read more. TECHNICAL […]
High-temperature superconductivity: Exploring quadratic electron-phonon coupling
Phys.org June 20, 2024 When the electron-phonon coupling is quadratic in the phonon coordinates, electrons can pair to form bipolarons due to phonon zero-point fluctuations. A team of researchers in the US (Harvard University, Connecticut University, MIT) studied superconductivity originating from this pairing mechanism in a minimal model and revealed that, in the strong coupling regime, the critical temperature () was only mildly suppressed by the coupling strength, in stark contrast to the exponential suppression in linearly coupled systems, thus implied higher optimal values. They demonstrated that large coupling constants of this flavor were achieved in known materials such as […]
A high-temperature superconductor with zero resistance that exhibits strange metal behavior
Phys.org June 25, 2024 In recent experimental signatures of superconductivity close to 80 K in La3Ni2O7 under pressure, a zero-resistance was not observed. Researchers in China showed that the zero-resistance state does exist in single crystals of La3Ni2O7. They found that the system remained metallic under applied pressures, suggesting the absence of a metal–insulator transition proximate to the superconductivity. Analysis of the normal state T-linear resistance revealed a link between this strange-metal behaviour and superconductivity. This was in line with other classes of unconventional superconductors, including the cuprates and Fe-based superconductors. According to the researchers further investigations exploring the interplay of […]