Phys.org May 12, 2022 Coupling between molecules and vacuum photon fields inside an optical cavity has proven to be an effective way to engineer molecular properties, in particular reactivity. An international team of researchers (Norway, Italy) studied optical cavities and how the light trapped in them interacts with atoms, molecules, and other particles. Their framework explained modifications of the electronic structure due to the interaction with the photon field. They showed that the newly developed orbital theory could be used to predict cavity induced modifications of molecular reactivity and pinpoint classes of systems with significant cavity effects. They also investigated […]
Physicists discover light-induced mechanism for controlling ferroelectric polarization
Phys.org May 10, 2022 Ferroelectric materials exhibit ferroelectricity and the ability to polarize spontaneously. Typically, researchers can manipulate and reverse the polarization by the application of an external electric field. Ultrafast interactions between light and matter are another promising route for controlling ferroelectric polarization, but until now researchers have struggled to achieve a light-induced, deterministic control of such polarization. An international team of researchers (USA – University of Arkansas, France, Luxembourg) discovered a so-called “squeezing effect” in ferroelectric materials subject to femtosecond laser pulses. These pulses destroyed the polarization component that is parallel to the field’s direction and created polarization […]
Quantum one-way street in topological insulator nanowires
Phys.org May 12, 2022 Recently quantum mechanical non-reciprocal transport effects that enable a highly controllable rectification were discovered. One such effect is magnetochiral anisotropy (MCA) in which the resistance of a material or a device depends on both the direction of the current flow and an applied magnetic field. However, the size of rectification possible due to MCA is usually extremely small because MCA relies on inversion symmetry breaking that leads to the manifestation of spin–orbit coupling, which is a relativistic effect. To overcome this limitation, an international team of researchers (Switzerland, Germany, Belgium) artificially broke the inversion symmetry via […]
Researchers find a way to form diodes from superconductors
Science Daily May 11, 2022 An international team of researchers (Italy, Spain, USA – MIT) has developed the quasi-particle counterpart, a superconducting tunnel diode with zero conductance in only one direction. The direction-selective propagation of the charge was obtained through the broken electron-hole symmetry induced by the spin selection of the ferromagnetic tunnel barrier: a EuS thin film separating a superconducting Al and a normal metal Cu layer. The Cu/EuS/Al tunnel junction achieved a large rectification (up to ∼40%) already for a small voltage bias (∼200 μV) due to the small energy scale of the system. With the help of an […]
Satellite mission finds that Tonga volcanic eruption effects reached space
Phys.org May 10, 2022 Analyzing data from NASA’s Ionospheric Connection Explorer (ICON) mission and ESA’s Swarm satellites, an international team of researchers (USA – UC Berkeley, University of Colorado, Germany) found that in the hours after the eruption, hurricane-speed winds and unusual electric currents formed in the ionosphere. Upon reaching the ionosphere and the edge of space, ICON clocked the windspeeds at up to 450 mph. After the eruption, the equatorial electrojet surged to five times its normal peak power and dramatically flipped direction, flowing westward for a short period. According to the researchers this is something we’ve only previously […]
Scientists discover a vast, salty groundwater system under the Antarctica ice sheet
Phys.org May 6, 2022 West Antarctic was an ocean before it was an ice sheet. So the bedrock below the ice sheet is covered with a thick layer of sediments. A team of researchers in the US (Colorado Schools of Mines, Scripps Institution of Oceanography) has found a huge amount of groundwater, including saltwater from the ocean in the thick layer of sediments. They suggested that there is a column of water about 220 to 820 meters (700 to 2,700 feet) deep. They estimated that most of this salty water arrived in the past 10,000 years, based on how much […]
Ultrafast ‘camera’ captures hidden behavior of potential ‘neuromorphic’ material
Phys.org May 9, 2022 A team of researchers in the US (Brookhaven National Laboratory, Duke University, Oak Ridge National Laboratory) captured the hidden trajectory of atomic motion of vanadium dioxide (VO2) as it transitioned from an insulator to a metal in response to a pulse of light. Vanadium dioxide exhibits an insulator-metal transition near room temperature in which a small voltage or current can produce a large change in resistivity with switching that can mimic the behavior of both neurons and synapses. Those are the signals produced by electrons scattering off the atoms of the vanadium dioxide sample as atoms […]
Uncovering the key to safer energy storage devices that avoid thermal runaway
Phys.org May 9, 2022 Researchers in South Korea investigated the thermal properties of electric double-layer capacitors (EDLCs) for a technical foundation in thermal measurement and revealed significant information. The reversible entropy and free energy changes in the EDLCs caused dynamic changes in the effective heat capacity of the electrodes, which were monitored in real-time during charge and discharge operations. In an EDLC with a 6 M KOH electrolyte, the effective heat capacities of the positive and negative electrodes with a varying voltage from 0 to 1 V were estimated to decrease by approximately 9.14% and 3.91%, respectively. This polarization dependence […]
Top 10 Science and Technology Inventions for the Week of May 6, 2022
01. Building a better quantum bit: New qubit breakthrough could transform quantum computing 02. Direct printing of nanodiamonds at the quantum level 03. Discovery of the one-way superconductor, thought to be impossible 04. A ‘beyond-quantum’ equivalence principle for superposition and entanglement 05. Thin quantum wires work better with less insulating coatings 06. A simpler approach for creating quantum materials 07. Hydrogen-tuned topological insulators may lead to new platforms in sustainable quantum electronics 08. Photons can enable real-time physical random bit generation for information security app 09. Perovskite photovoltaics for a greener Internet-of-Things 10. Zero-index metamaterials offer new insights into the […]
A ‘beyond-quantum’ equivalence principle for superposition and entanglement
Phys.org May 2, 2022 An international team of researchers (France, Germany, Spain) has discovered a new connection between superposition and entanglement that does not assume that quantum theory is correct. They proved that given any two general probabilistic theories (GPTs) the following are equivalent: (i) each theory is nonclassical, (ii) each theory satisfies a strong notion of incompatibility equivalent to the existence of “superpositions” and (iii) the two theories can be entangled, in the sense that their composite exhibits either entangled states or entangled measurements. Intuitively, in the post-quantum GPT setting, a superposition is a set of two binary ensembles […]