6 research outputs found
Crossover from Josephson Effect to Single Interface Andreev Reflection in Asymmetric Superconductor/Nanowire Junctions
We report on the fabrication and
characterization of symmetric
nanowire-based Josephson junctions, that is, Al- and Nb-based junctions,
and asymmetric junctions employing superconducting Al and Nb. In the
symmetric junctions, a clear and pronounced Josephson supercurrent
is observed. These samples also show clear signatures of subharmonic
gap structures. At zero magnetic field, a Josephson coupling is found
for the asymmetric Al/InAs-nanowire/Nb junctions as well. By applying
a magnetic field above the critical field of Al or by raising the
temperature above the critical temperature of Al the junction can
be switched to an effective single-interface superconductor/nanowire
structure. In this regime, a pronounced zero-bias conductance peak
due to reflectionless tunneling has been observed
Electronic Transport with Dielectric Confinement in Degenerate InN Nanowires
In this Letter, we present the size effects on charge
conduction
in InN nanowires by comprehensive transport studies supported by theoretical
analysis. A consistent model for highly degenerate narrow gap semiconductor
nanowires is developed. In contrast to common knowledge of InN, there
is no evidence of an enhanced surface conduction, however, high intrinsic
doping exists. Furthermore, the room-temperature resistivity exhibits
a strong increase when the lateral size becomes smaller than 80 nm
and the temperature dependence changes from metallic to semiconductor-like.
This effect is modeled by donor deactivation due to dielectric confinement,
yielding a shift of the donor band to higher ionization energies as
the size shrinks
Extreme ultraviolet interference lithography at the Paul Scherrer Institut
Auzelyte V, Dais C, Farquet P, et al. Extreme ultraviolet interference lithography at the Paul Scherrer Institut. JOURNAL OF MICRO-NANOLITHOGRAPHY MEMS AND MOEMS. 2009;8(2):021204.We review the performance and applications of an extreme ultraviolet interference lithography (EUV-IL) system built at the Swiss Light Source of the Paul Scherrer Institut (Villigen, Switzerland). The interferometer uses fully coherent radiation from an undulator source. 1-D (line/space) and 2-D (dot/hole arrays) patterns are obtained with a transmission-diffraction-grating type of interferometer. Features with sizes in the range from one micrometer down to the 10-nm scale can be printed in a variety of resists. The highest resolution of 11-nm half-pitch line/space patterns obtained with this method represents a current record for photon based lithography. Thanks to the excellent performance of the system in terms of pattern resolution, uniformity, size of the patterned area, and the throughput, the system has been used in numerous applications. Here we demonstrate the versatility and effectiveness of this emerging nanolithography method through a review of some of the applications, namely, fabrication of metallic and magnetic nanodevice components, self-assembly of Si/Ge quantum dots, chemical patterning of self-assembled monolayers (SAM), and radiation grafting of polymers. (c) 2009 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3116559