Application of double patterning technology to fabricate optical elements: Process simulation, fabrication, and measurement J. Vac. Sci. Technol. B 30, 031605 (2012); 10.1116/1.3698315 Imaging classical and quantum structures in an open quantum dot using scanning gate microscopy

One problem in superconducting tunnel junction x-ray detectors is that the two electrodes respond differently to monochromatic x-rays, and produce double peaks in energy spectra. To study the double peak phenomenon, Low Temperature Scanning Electron Microscope (LTSEM) is a versatile tool, since it is possible to analyze two electrodes separately. From the LTSEM analyses in combination with x-ray detection experiments, it has been revealed that the intrinsic charge output of the base electrode is higher than that of the counter electrode over a wide range of bias voltages in our Nb/Al polycrystalline junctions. The voltage dependence of charge output is considerably modified by flux quanta trapped in a terrestrial magnetic field.

No abstract

Tunneling of nonequilibrium quasiparticles excited by x-ray quanta in a nonsymmetric superconducting tunnel detector Low Temp.It has been normally observed that superconducting tunnel junction x-ray detectors produce a double peak originating from different absorption events in two electrodes. The double peak is associated with the dynamics of quasiparticles created by x-ray absorption events. In this study we have found that the double peak phenomenon depends on both bias voltage and magnetic history. On the events in the base and counterelectrodes the detector exhibits dissimilar signal-height versus bias-voltage characteristics, which suffer a large change when a small number of Abrikosov vortices corresponding to even a terrestrial magnetic field are frozen during cooling. These observations are explained by a multiple quasiparticle tunneling model with quasiparticle trapping in the vortices.

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication Citation for published version (APA):Panteleit, F., Schroeder, T., Martin, J., Huebener, R. P., Kiewiet, F. B., Berg, van den, M. L., & Korte, P. A. J. (1999). Quasiparticle losses at the surface of superconducting tunnel junction detectors. Journal of Applied Physics, 85(1), 565-570. DOI: 10.1063/1.369490 General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Superconducting tunnel junctions ͑STJs͒ are promising as high energy resolution x-ray detectors. However, the theoretical limit of the energy resolution of STJs has not yet been reached for several reasons. In many cases quasiparticle losses limit the energy resolution. We have investigated STJs with different multilayer structures by means of low temperature scanning electron microscopy. By measuring the quasiparticle lifetime of Nb junctions with and without Ta passivation at the surface, we have identified quasiparticle losses at the surface of nonpassivated junctions as the dominant loss process. The temperature dependence of the quasiparticle lifetime gives information about the loss mechanism. The influence of quasiparticle traps on the effective quasiparticle lifetime is discussed.