3,151 research outputs found
Josephson current via an isolated Majorana zero mode
No full textWe study the equilibrium dc Josephson current in a junction between an s-wave and a topological superconductor. Cooper pairs from the s-wave superconducting lead can transfer to the topological side either via an unpaired Majorana zero mode localized near the junction or via the above-gap continuum states. We find that the Majorana contribution to the supercurrent can be switched on when time-reversal symmetry in the conventional lead is broken, e.g., by an externally applied magnetic field inducing a Zeeman splitting. Moreover, if the magnetic field has a component in the direction of the effective spin-orbit field, there will be a Majorana-induced anomalous supercurrent at zero phase difference. These behaviors may serve as a signature characteristic of Majorana zero modes and are accessible to devices with only superconducting contacts.QRD/Wimmer GroupBUS/Quantum Delf
A Comparison Theorem For Matrix Riccati Difference-equations
No full textDifference equations of the form X(t) = F*(t)X(t - 1)F(t) - F*(t)X(t - 1)G(t)[I + G*(t)X(t - 1)G(t)]-1G*(t)X(t - 1)F(t) + Q(t) and their associated Hermitian matrices H(t) = (Q(F)F*-GG*)(t) are studied. Solution Of different Riccati equations can be compared if the difference of their corresponding Hermitian matrices is semidefinite for all t. An application to the discrete-time LQ optimal control problem is given
Wimmer Building
No full textThe Hoosier Tire Company is located on the first floor of the building. Two cars are parked along the curb. A large sign on top of the building reads "Wimmer Building - Merchants Heat & Light Co.
Continuous dependence of sets of solutions of the algebraic Riccati equation
No full textIl Poligrafo, Padova, A. Beghi, L. Finesso and G. Picci Eds
Suboptimal Markovian smoothing estimates based on continuous curves of solutions of the Algebraic Riccati Equation
No full textBased on a result on continuous dependence of solutions of an algebraic Riccati equation on the data matrices, we construct continuous
curves of solutions of an algebraic Riccati inequality, and derive suboptimal Markovian estimates for the steady-state smoothing problem
Enlightenment and/or Empire: two German perspectives on the Australian aborigines
No full textGerman citation: Australien: Realität – Klischee – Vision, 2012 / Henriette von Holleuffer and Adi Wimmer (eds.), pp.153-166 KOALAS – Konzepte, Orientierungen, Abhandlungen, Lektüren, Australien-Studien [Concepts, Orientations, Treatises, Readings, Australian Studies]http://www.wvttrier.de/top/Beschreibungen/ID1277.htm
Unified numerical approach to topological semiconductor-superconductor heterostructures
No full textWe develop a unified numerical approach for modeling semiconductor-superconductor heterostructures. All the key physical ingredients of these systems - orbital effect of magnetic field, superconducting proximity effect, and electrostatic environment - are taken into account on equal footing in a realistic device geometry. As a model system, we consider indium arsenide (InAs) nanowires with an epitaxial aluminum (Al) shell, which is one of the most promising platforms for Majorana zero modes. We demonstrate qualitative and quantitative agreement of the obtained results with the existing experimental data. Finally, we characterize the topological superconducting phase emerging in a finite magnetic field and calculate the corresponding topological phase diagram.QRD/Wimmer Grou
Order reduction of discrete-time algebraic Riccati equations with singular closed loop matrix
No full textWe study the general discrete-time algebraic Riccati equation and deal with the case where the closed loop matrix corresponding to an arbitrary solution is singular. In this case the extended symplectic pencil associated with the DARE has 0 as a characteristic root and the corresponding spectral deflating subspace gives rise to a subspace where all solutions of the DARE coincide. This allows for a reduction of the original DARE to an equation of smaller size
H /e Superconducting Quantum Interference through Trivial Edge States in InAs
No full textJosephson junctions defined in strong spin orbit semiconductors are highly interesting for the search for topological systems. However, next to topological edge states that emerge in a sufficient magnetic field, trivial edge states can also occur. We study the trivial edge states with superconducting quantum interference measurements on nontopological InAs Josephson junctions. We observe a SQUID pattern, an indication of superconducting edge transport. Also, a remarkable h/e SQUID signal is observed that, as we find, stems from crossed Andreev states.QRD/Kouwenhoven LabQRD/Wimmer Grou
Mit Bezug auf Sprache. Festschrift für Rainer Wimmer
No full textDie Beiträge in der Festschrift für Rainer Wimmer anlässlich seines 65. Geburtstags dokumentieren die Vielschichtigkeit seines sprachwissenschaftlichen Wirkens. Eine große Anzahl der Artikel widmet sich einer seiner zentralen Forschungstätigkeiten, der Sprachkritik. Seine interdisziplinären und anwendungsorientierten Arbeitsfelder sowie seine frühen Arbeiten zu Eigennamen werden durch spezifische Beiträge ebenso gewürdigt, wie in einem Themenblock hervorgehoben wird, dass es »die« Sprache nicht gibt, sondern dass Sprachen nur neben Sprachen, d. h. in einem Miteinander, existieren können.
Auf diese Weise entsteht ein Einblick in die wichtigsten Strömungen und Ansätze der zeitgenössischen interpretativen Semantik, zu deren Entwicklung Rainer Wimmer durch sein Schaffen wesentlich beigetragen hat
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