Nanowerk June 26, 2024 Hybrid glasses derived from meltable metal-organic frameworks (MOFs) promise to combine the intriguing properties of MOFs with the universal processing ability of glasses. Researchers in Germany developed optical-quality glasses derived from the zeolitic imidazole framework which allowed them to perform in-depth studies of optical transparency and refraction across the ultraviolet to near-infrared spectral range. Using this fundamental data, they demonstrated the fabrication of micro-optical devices by thermal imprinting. They showed that concave as well as convex lens structures could be obtained at high precision by remelting the glass without trading-off on material quality. This enabled multifunctional […]
Tag Archives: S&T Germany
Technologies for the future of aerospace
Fraunhofer News May 29, 2024 At the 2024 ILA Berlin aerospace expo, to be held from June 5 to 9 the Fraunhofer-Gesellschaft will be showcasing nearly 50 exhibits from various disciplines and fields of research. They are scheduled to present urban aviation systems, satellite technology for quantum encryption, and a drone used to detect forest fires, among other solutions. They will demonstrate how cutting-edge research combines practical solutions with cost-effectiveness and climate action. Fraunhofer researchers are also active in the field of defense and security, where they will be presenting technologies for detection and defense against hypersonic weapons… read more.
Physicists reach atomic-scale telegraphy with light
Phys.org May 8, 2024 By exploiting linear interaction with tip-confined evanescent light fields, near-field microscopy has reached even higher resolution, prompting a vibrant research field by exploring the nanocosm in motion. Yet the finite radius of the nanometre-sized tip apex has prevented access to atomic resolution. Researchers in Germany leveraged extreme atomic nonlinearities within tip-confined evanescent fields to push all-optical microscopy to picometric spatial and femtosecond temporal resolution. They discovered an unprecedented and efficient non-classical near-field response, in phase with the vector potential of light and strictly confined to atomic dimensions. This ultrafast signal was characterized by an optical phase […]
Quantum precision: A new kind of resistor
Nanowerk April 15, 2024 Metrological applications of the quantum anomalous Hall effect are currently restricted by the need for low measurement currents and low temperatures. Researchers in Germany developed a measurement scheme that increases the robustness of a zero-magnetic-field quantum anomalous Hall resistor and extends its operating range to higher currents. In the scheme, they simultaneously injected current into two disconnected perimeters of a multi-terminal Corbino device to balance the electrochemical potential between the edges. This screened the electric field that drove backscattering through the bulk and thus improved the stability of the quantization at increased currents. According to the […]
Quantum dance to the beat of a drum: Researchers observe how energy of single electron is tuned by surrounding atoms
Phys.org March 14, 2024 Direct observation of the relevant interplay of the electronic structure of a single defect with other microscopic elementary excitations on their intrinsic length, time and energy scales has not been achieved. Researchers in Germany directly resolved in space, time, and energy how a spin–orbit-split energy level of an isolated selenium vacancy in a moiré-distorted WSe2 monolayer evolved under the controlled excitation of lattice vibrations. By locally launching a phonon oscillation and taking ultrafast energy-resolved snapshots of the vacancy’s states faster than the vibration period, they directly measured the impact of electron–phonon coupling in an isolated single-atom […]
A 3D view into chaos: Researchers visualize temperature-driven turbulence in liquid metal for the first time
Phys.org March 11, 2024 Researchers in Germany conducted an experiment inside a cylinder filled with the ternary alloy GaInSn focusing on the manifestation and dynamics of the large-scale circulation (LSC) in turbulent liquid metal convection. The large-scale flow structures were classified and characterized at Rayleigh numbers by means enabling the full reconstruction of the three-dimensional flow structures in the entire convection cell. They identified the dominating modes of the turbulent convection. The analysis revealed that a single-roll structure of the LSC alternates in short succession with double-roll structures or a three-roll structure. This was accompanied by dramatic fluctuations of the […]
Making quantum bits fly
Nanowerk March 6, 2024 Matter qubit to traveling photonic qubit conversion is the cornerstone of numerous quantum technologies such as distributed quantum computing, as well as several quantum internet and networking protocols. Researchers in Germany formulated a theory for stimulated Raman emission which is applicable to a wide range of physical systems, including quantum dots, solid-state defects, and trapped ions, and various parameter regimes. They found the upper bound for the photonic pulse emission efficiency of arbitrary matter qubit states for imperfect emitters and showed a path forward to optimizing the fidelity. Based on these results, they proposed a paradigm […]
Measuring the properties of light: Scientists realize new method for determining quantum states
Nanowerk February 25, 2024 Superconducting nanowire single-photon detectors (SNSPDs) have been widely used to study the discrete nature of quantum states of light in the form of photon-counting experiments. Researchers in Germany showed that SNSPDs can also be used to study continuous variables of optical quantum states by performing homodyne detection at a bandwidth of 400 kHz. By measuring the interference of a continuous-wave field of a local oscillator with the field of the vacuum state using two SNSPDs, they showed that the variance of the difference in count rates was linearly proportional to the photon flux of the local […]
A new record for atom-based quantum computers: 1,000 atomic qubits and rising
Phys.org February 15, 2024 Researchers in Germany designed a large-scale quantum-processing architecture surpassing the tier of 1000 atomic qubits. By tiling multiple microlens-generated tweezer arrays, each operated by an independent laser source, they eliminated laser-power limitations in the number of allocatable qubits. With two separate arrays, they implemented combined 2D configurations of 3000 qubit sites with a mean number of 1167(46) single-atom quantum systems. The transfer of atoms between the two arrays effectively. Supercharging one array designated as the quantum processing unit with atoms from the secondary array significantly increased the number of qubits and the initial filling fraction. They […]
Physicists develop new solar cell design for better efficiency
Phys.org February 20, 2024 Photovoltaics offers a large potential for the supply of clean and renewable energy. Silicon solar cells used for this purpose have efficiency limits. One reason for this is that some of the energy from short-wave radiation is not converted into electricity, but into unwanted heat. Through computer simulation researchers in Germany showed that to increase the efficiency, the silicon solar cell could be provided with an organic layer, for example made from the semiconductor tetracene. Short-wave light is absorbed in this layer and converted into high-energy excitons. These excitons decay in the tetracene into two low-energy […]