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Superconducting TES array X-ray spectrometer goes into operation at BESSY II

Europe’s first and only TES spectrometer at a synchrotron source is now in operation at BESSY II, developed within a collaboration between the HZB, the MPI-CEC (Mühlheim-an-der-Ruhr, Germany) and the NIST (Boulder, Colorado, U.S.). The photon detection efficiency of the new instrument exceeds that of wavelength-dispersive X-ray emission spectrometers by a factor of 100 to 1,000. It will be used to investigate the electronic properties of atomically thin layers, nanostructures and highly diluted atomic and molecular samples. The team is looking forward to receiving exciting research proposals from the user community.

Synchrotron radiation sources such as BESSY II provide intense, highly brilliant X-ray light that can be used to examine a wide variety of samples. However, X-ray emission spectroscopy (XES) and Resonant Inelastic X-ray Scattering (RIXS), where the photons emitted from the sample are detected, are extremely photon-hungry techniques. Therefore, XES and RIXS have so far been largely limited to high-concentration and bulk samples. The details are presented in the journal Review of Scientific Instruments.

Flexible cryogenic cables for dilution refrigerators could pave path to practical quantum computers

Necessary for quantum system development is an environment in which the fragile nature of quantum bits (qubits) is stabilized and the thermal noise (fluctuations in current/voltage) inherent in superconducting electronics is dampened. That environment requires cryogenic temperatures, those ranging from 5 to 10 millikelvins, colder than the extreme temperatures encountered in space. Dilution refrigerators create this needed cryogenic condition.

Dilution refrigerators used for quantum R&D need a wiring system that can operate in cryogenic temperatures, maintain a power-efficient direct current, and support high-speed data transmission. Researchers at MIT Lincoln Laboratory have prototyped flexible, ribbon-like, low-frequency (LF) cables that not only meet these demands, but also are compatible with commercial circuit-board manufacturing processes. Maybell Quantum, a Colorado-based company supplying hardware for developing quantum systems, licensed the design for these cables and is adapting them for use in their dilution refrigerators.

New plasma trick could unlock smaller, more powerful computer chips

Under carefully controlled conditions, particles within a plasma can strike the surface of a TMD material and knock atoms loose. The challenge is achieving enough energy to remove sulfur atoms from the top layer without harming the molybdenum layer beneath. Because the difference between success and damage is so small, developing a reliable process has proven difficult.

Using computer simulations, researchers found that treating molybdenum disulfide with oxygen or fluorine before plasma exposure can make the process much more controlled. Their findings were published in the Journal of Physical Chemistry Letters.

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