Phys.org July 26, 2021 An international team of researchers (USA – Yale University, the Netherland, Spain, Denmark, Sweden) experimentally demonstrated a new qubit that fuses the electromagnetic modes of superconducting circuits and the spins of small numbers of electrons trapped in semiconductor quantum dots. They were able to show how to harness this spin-dependent supercurrent to achieve both spin detection and coherent spin manipulation. The work represents a significant advancement to our understanding and control of Andreev levels which are microscopic, electronic states that exist in all Josephson junctions. In superconductor-semiconductor heterostructures such as the nanowire junctions investigated in this […]
Author Archives: Hema Viswanath
Dancing with the light: A new way to make crystals bend by shining light
Nanowerk July 30, 2021 Only very thin crystals (up to 20 microns) can show appreciable mechanical response. Researchers in Japan accidentally discovered that the photothermal effect causes a crystal to bend fast. To create a new, faster bending crystal and clarify the underlying mechanism, they exposed a thin salicylideneaniline derivative crystal to UV light and obtained substantial bending within approximately 1 second. However, the bend angle dropped rapidly with increasing crystal thickness, revealing that the bending was caused by photoisomerization. When they illuminated a thick (>40 microns) crystal with UV light, they observed an extremely rapid bending within several milliseconds, […]
Earth’s interior is swallowing up more carbon than thought
Phys.org July 26, 2021 The best-understood parts of the carbon cycle are at or near Earth’s surface, but deep carbon stores play a key role in maintaining the habitability of our planet by regulating atmospheric CO2 levels. An international team of researchers (UK, Germany, China, France, Switzerland, Singapore) conducted a series of experiments that support growing evidence that carbonate rocks become less calcium-rich and more magnesium-rich when channeled deeper into the mantle. This chemical transformation makes carbonate less soluble meaning it doesn’t get drawn into the fluids that supply volcanoes. Instead, most of the carbonate sinks deeper into the mantle […]
Molecular library of OLED host materials
Nanowerk July 27, 2021 OLED pixels normally consist of multiple layers which ensure, for example, that electrons can travel in the pixel with as little resistance as possible. The fine-tuning of the layer properties, for example, electron mobility or the emitted wavelength (color of the light), is a complex task. An international team of researchers (South Korea, Ukraine, Belgium, Germany) compared a wide range of computer-simulated and experimentally measured properties of OLED thin films, trying to understand whether OLED design can be guided solely by computer. They established a molecular library of typical OLED materials to streamline the design of […]
A new information storage and processing device
Phys.org July 29, 2021 An international team of researchers (USA – New York University, UC San Diego, France) combined the unique properties of quantum materials together with that of spintronic magnetic devices. They presented spin torque ferromagnetic resonance characteristics of a hybrid metal-insulator-transition oxide/ ferromagnetic metal nano constriction. Their samples incorporate vanadium trioxide (V2O3), with Ni, Permalloy (Ni80Fe20) and platinum layers patterned into a nano constriction geometry. The first order phase transition in V2O3 is shown to lead to systematic changes in the resonance response and hysteretic current control of the ferromagnetic resonance frequency. The output signal can be systematically […]
Physicists Have Developed a New Way to Levitate Objects Using Sound Only
Science Alert July 26, 2021 There are significant limitations hindering acoustic tweezers for broad practical application. Although hemispherical arrays of acoustic transducers can be used to create the sound trap, creating just the right sound field to lift an object and move it far from the transducers is very difficult if there is a surface that reflects sound. Researchers in Japan have developed a technique splitting the transducer array into blocks and used an inverse filter to reproduce sounds based on the acoustic waveform. This helps optimize the phase and amplitude of each transducer channel to produce the desired acoustic […]
To de-ice planes on the fly, researchers aim to control rather than combat ice formation
Phys.org July 26, 2021 A team of researchers in the US (Virginia Tech, UC Santa Barbara) created a de-icing method based on Cassie’s Law, which shows that air can be trapped under water drops if the drops are suspended atop a structure that is bumpy and water-repellent. They sought to make ice form in a layer with lower adhesion to the surface. They created an array of pillars, each one millimeter tall by half a millimeter wide. The tiny pedestals were machined into a pattern with a millimeter between the pillars. As the temperature dropped, frost preferentially grew on the […]
New quantum research gives insights into how quantum light can be mastered
Phys.org July 22, 2021 Researchers at Los Alamos National Laboratory propose that modulated quantum metasurfaces can control all properties of photonic qubits, a breakthrough that could impact the fields of quantum information, communications, sensing and imaging, as well as energy and momentum harvesting. They developed a metasurface that looked like an array of rotated crosses, then proposed to shoot a single photon through the metasurface, where the photon splits into a superposition of many colors, paths, and spinning states generating quantum entanglement meaning the single photon can inherit different properties at once. According to the researchers by manipulating these properties, […]
The quantum refrigerator
Science Daily July 29, 2021 An international team of researchers (Germany, Austria, Portugal, Singapore) has provided a detailed proposal of how to realize a quantum machine in one-dimensional ultracold atomic gases, which consists of a set of modular operations giving rise to a piston. These can then be coupled sequentially to thermal baths, with the innovation that a quantum field takes up the role of the working fluid. They proposed models for compression on the system to use it as a piston and coupling to a bath that gives rise to a valve controlling heat flow. By composing the numerically […]
Spin-sonics: Acoustic wave gets the electrons spinning
Phys.org July 29, 2021 An international team of researchers (Germany, Canada, USA – Perdue University) has detected the rolling movement of a nano-acoustic wave predicted by Lord Rayleigh in 1885. They used an extremely fine nanowire that was positioned on lithium niobate, a piezoelectric material, which becomes deformed when subjected to an electrical current. With the aid of small metal electrodes, an acoustic wave can be generated on the material. The acoustic wave generates an elliptically rotating electrical field. This, in turn, forces the electrons in the nanowire onto circular paths. So far, this phenomenon was seen in light. Now […]