Revealing charge-tunneling processes between a quantum dot and a superconducting island through gate sensing

We report direct detection of charge-tunneling between a quantum dot and a superconducting island through radio-frequency gate sensing. We are able to resolve spin-dependent quasiparticle tunneling as well as two-particle tunneling involving Cooper pairs. The quantum dot can act as an RF-only sensor to characterize the superconductor addition spectrum, enabling us to access subgap states without transport. Our results provide guidance for future dispersive parity measurements of Majorana modes, which can be realized by detecting the parity-dependent tunneling between dots and islands.Comment: 6 pages, 4 figures, supplemental material included as ancillary fil

Structural evolution and strain induced mixing in Cu-Co composites studied by transmission electron microscopy and atom probe tomography

A Cu-Co composite material is chosen as a model system to study structural evolution and phase formations during severe plastic deformation. The evolving microstructures as a function of the applied strain were characterized at the micro-, nano-, and atomic scale-levels by combining scanning electron microscopy and transmission electron microscopy including energy-filtered transmission electron microscopy and electron energy-loss spectroscopy. The amount of intermixing between the two phases at different strains was examined at the atomic scale using atom probe tomography as complimentary method. It is shown that Co particles are dissolved in the Cu matrix during severe plastic deformation to a remarkable extent and their size, number, and volume fraction were quantitatively determined during the deformation process. From the results, it can be concluded that supersaturated solid solutions up to 26 at.% Co in a fcc Cu-26 at.% Co alloy are obtained during deformation. However, the distribution of Co was found to be inhomogeneous even at the highest degree of investigated strain

Rechnungslegung nach OR: Grundsatz der Unternehmensfortführung Teil 1

Die Jahresrechnung beruht auf der Annahme, dass das Unternehmen auf absehbare Zeit, mindestens aber in den nächsten zwölf Monaten ab dem Bilanzstichtag fortgeführt werden kann. Es stellt sich die Frage, wer für die Beurteilung der Unternehmensfortführung verantwortlich ist und welcher Prognosezeitraum zugrunde gelegt werden muss

Rechnungslegung nach OR: Grundsatz der Unternehmensfortführung Teil 2

Die Jahresrechnung beruht auf der Annahme, dass das Unternehmen auf absehbare Zeit, mindestens aber in den nächsten zwölf Monaten ab dem Bilanzstichtag fortgeführt werden kann. Es stellt sich die Frage, wie zu verfahren ist, wenn die Fortführungsannahme zu verneinen ist

Beam Pattern Optimization Method for Subarray-Based Hybrid Beamforming Systems

Massive multiple-input multiple-output (MIMO) systems operating at millimeter-wave (mmWave) frequencies promise to satisfy the demand for higher data rates in mobile communication networks. A practical challenge that arises is the calibration in amplitude and phase of these massive MIMO systems, as the antenna elements are too densely packed to provide a separate calibration branch for measuring them independently. Over-the-air (OTA) calibration methods are viable solutions to this problem. In contrast to previous works, the here presented OTA calibration method is investigated and optimized for subarray-based hybrid beamforming (SBHB) systems. SBHB systems represent an efficient architectural solution to realize massive MIMO systems. Moreover, based on OTA scattering parameter measurements, the ambiguities of the phase shifters are exploited and two criteria to optimize the beam pattern are formulated. Finally, the optimization criteria are examined in measurements utilizing a novel SBHB receiver system operating at 27.8 GHz

Of “raisins” and “yeast”: mobilisation and framing in the East German revolution of 1989

There is no shortage of literature on the social movements that arose in East Germany in 1989. Numerous studies have shed light upon the nature, scale and dynamics of the uprising of that year. But on certain issues questions remain. No consensus exists, for example, on the relationship between the “civic groups” (New Forum, Democratic Awakening, etc.) and the street protests of the autumn of 1989. Were these simply two facets of a single movement? Or are they better characterised as two distinct streams within the same movement delta? Did the street protests push the civic movement activists into the limelight? Or is it more accurate to say, with Reinfried Musch, that “the civic movement brought the people onto the streets”?1 This paper considers two contrasting interpretations of these issues, and finds both wanting. An alternative interpretation is offered, one that draws upon Marc Steinberg's “dialogical” development of frame theory

Implementation-level Analysis of the JavaScript Helios Voting Client

We perform the first automated security analysis of the actual JavaScript implementation of the Helios voting client, a state-of-the-art, web-based, open-audit voting system that is continuously being deployed for real-life elections. While its concept has been exhaustively analyzed by the security community, we actively analyze its actual JavaScript implementation. Automatically ascertaining the security of a large-scale JavaScript implementation comes with major technical challenges. By creating a sequence of program transformations, we overcome these challenges, thereby making the Helios JavaScript client accessible to existing static analysis techniques. We then automatically analyze the transformed client using graph slicing, reducing an approximately 7 million node graph representing the information flow of the client’s implementation to a handful of potentially harmful flows, each individually consisting of less than 40 nodes. Our interpretation of this analysis results in the exposure of two thus far undiscovered vulnerabilities affecting the live version of Helios: a serious cross-site scripting attack leading to arbitrary script execution and a browser-dependent execution path that results in ballots being sent in plaintext. These attacks can be mitigated with minor adaptations to Helios. Moreover, our program transformations result in a version of Helios with fewer external dependencies and, accordingly, a reduced attack surface