Eurekalert March 3, 2020 Researchers in Germany discovered that skyrmions and antiskyrmions are stabilized in different materials by a magnetic interaction that is directly tied to the structure of the host material. However, what was previously overlooked is that the magnetic dipoles also significantly interact with each other via their dipole-dipole interaction. This interaction always prefers skyrmions. For this reason, even “antiskyrmion materials” can exhibit skyrmions (but not vice versa). This happens preferably as the temperature is lowered. At a critical transition temperature, the two distinct objects coexist. The finding allows for an advanced version of the racetrack memory data […]
Tag Archives: S&T Germany
Extending Quantum Entanglement Across Town
IEEE Spectrum February 4, 2020 In an experiment researchers in Germany transferred the information contained in a single quantum bit from an atomic state to a single photon, then sent it through some 20 kilometers of fiber optic cable. They generated and observed the entanglement between a rubidium atom and a photon whose wavelength was transformed from 780 nm to the telecom S band at 1522 nm. The researchers found they can preserve on average some 78 percent of the entanglement between the rubidium atom and the fiber optic photon. Their next steps are to build out the full atom-to-photon-to-atom […]
On the way to quantum networks
Phys.org January 24, 2020 Entanglement between stationary quantum memories and photonic channels is the essential resource for future quantum networks. Together with entanglement distillation, it will enable efficient distribution of quantum states. Researchers in Germany entangled a rubidium atom with a photon and were able to detect the entangled state—which now shares the quantum properties of both particles—after its passage through a 20-km coil of optic fiber. Rubidium atoms emit photons with a wavelength of 780 nanometers which is rapidly absorbed. They built a quantum frequency converter that was specifically designed to increase the wavelength of the emitted photons from […]
New approach for controlling qubits via microwave pulses reduces error rates and increases efficiency
Phys.org January 10, 2020 Microwave trapped-ion quantum logic gates avoid spontaneous emission as a fundamental source of decoherence. However, microwave two-qubit gates are still slower than laser-induced gates and hence more sensitive to fluctuations and noise of the motional mode frequency. In order to reduce error rates even further and provide reliable operations much faster researchers in Germany have developed a method where ions are trapped under vacuum by using electric fields above a chip structure. Qubit operations are implemented by sending microwave signals through special conductor loops embedded in the chip structure. Using microwave fields has the advantage that […]
Nano antennas for data transfer
Science Daily January 8, 2020 To enable antennas to operate at higher frequencies allow higher bandwidths and smaller footprints directional antennas have to be shrunk to nanometre scale. Researchers in Germany demonstrated electrically driven Yagi-Uda antennas for light with wavelength-scale footprints that exhibit large directionalities with forward-to-backward ratios of up to 9.1 dB. Light generation is achieved via antenna-enhanced inelastic tunneling of electrons over the antenna feed gap. They obtained reproducible tunnel gaps by means of feedback-controlled dielectrophoresis to precisely place single surface-passivated gold nanoparticles in the antenna gap. The resulting antennas performed equivalent to radio-frequency antennas and outperformed RF designs. […]
An alloy that retains its memory at high temperatures
Science Daily December 3, 2019 In the conventional high-temperature shape memory alloy Ti-Ta, the formation of this phase compromises completely the shape memory effect. Addition of other elements to form Ti-Ta-X alloys often modifies the transformation temperatures. Researchers in Germany used transparent descriptors derived from first-principles calculations to search for new ternary Ti-Ta-X alloys that combine stability and high temperatures. They suggest four alloys with these properties, namely Ti-Ta-Sb, Ti-Ta-Bi, Ti-Ta-In, and Ti-Ta-Sc. Their predictions for the most promising of these alloys, Ti-Ta-Sc, are subsequently fully validated by experimental investigations showing no traces of omega phase after cycling. Their computational […]
Novel memory device can be written on and read out optically or electrically
Science Daily November 25, 2019 Researchers in Germany have demonstrated a new type of programmable organic capacitive memory called p‐i‐n‐metal‐oxide‐semiconductor (pinMOS) memory with the possibility to store multiple states. It can be written as well as read electrically and optically. The device shows excellent repeatability, an endurance of more than 104 write‐read‐erase‐read cycles, and currently already over 24 hours retention time. The working mechanism of the pinMOS memory under dynamic and steady‐state operations is investigated to identify further optimization steps. The results reveal that the pinMOS memory principle is promising as a reliable capacitive memory device for future applications in […]
Meet the Volocity
IEEE Spectrum November 12, 2019 VoloCity is an inner-city flying taxi proposed by a German company. The wide span and 9 Lithium-ion exchangeable battery packs-powered engines and rotors (18 of each) reduce the noise level. The aircraft will fly at “only” 110kmph. Batteries are recharged on the vertiports. Vertical take-off and landing, so no need for wheels nor retractable landing gear…read more.
New liquid crystals allowing directed transmission of electricity synthesized
Science Daily October 1, 2019 Researchers in Germany have synthesized novel liquid crystals in which the molecules align in a self-assembly process to form columns when it is cooled slowly. The columns conduct electrical energy by electrons along their whole length. The materials can serve as organic, liquid crystalline “power cables” and provide targeted electricity transmission in electronic components. The liquid crystalline power cable will heal entirely by itself if it ruptures. If a single molecule is stimulated by exposure to UV light, it will glow in response. If the concentration of the molecule increases, this effect disappears only to […]
Preventing manipulation in automated face recognition
Fraunhofer Research October 1, 2019 In morphing processes two facial images are melded into a single synthetic facial image that contains the characteristics of both persons. As a result, biometric face recognition systems authenticate the identity of both persons based on this manipulated photo. Morphing attacks can take place before or during the process of applying for an ID document. To address this problem researchers in Germany are developing a process that identifies the image anomalies that occur during digital image processing focusing on analyzing and researching simulated imaging data using image processing, machine learning methods, and deep neural networks […]