217 research outputs found
Spin polarized photoelectrons with unpolarized light in normal emission from Pt(110)
Irmer N, Frentzen F, Schmiedeskamp B, Heinzmann U. Spin polarized photoelectrons with unpolarized light in normal emission from Pt(110). Surface Science. 1994;307-309(2):1114-1117.The normally emitted photoelectrons of the reconstructed (1 x 2) surface of Pt(110) caused by off-normally incoming, unpolarized light are spin polarized. Measurements have been performed with the light of a gas discharge tube and spin polarization of up to 20% has been found for the spin polarization perpendicular to the reaction plane, defined by the momenta of incoming photon and outgoing electron beam. The polarization depends significantly on a rotation of the crystal about the surface normal. The experimental data are in good agreement with theoretical calculations of Feder's group [1] based upon the theory describing the photoemission in the one-step model
Josephson Junctions defined by a Nano-Plough
We define superconducting constrictions by ploughing a deposited Aluminum
film with a scanning probe microscope. The microscope tip is modified by
electron beam deposition to form a nano-plough of diamond-like hardness, what
allows the definition of highly transparent Josephson junctions. Additionally a
dc-SQUID is fabricated to verify appropriate functioning of the junctions. The
devices are easily integrated in mesoscopic devices as local radiation sources
and can be used as tunable on-chip millimeter wave sources
Microwave spectroscopy on a double quantum dot with an on-chip Josephson oscillator
We present measurements on microwave spectroscopy on a double quantum dot
with an on-chip microwave source. The quantum dots are realized in the
two-dimensional electron gas of an AlGaAs/GaAs heterostructure and are weakly
coupled in series by a tunnelling barrier forming an 'ionic' molecular state.
We employ a Josephson oscillator formed by a long Nb/Al-AlO/Nb junction as
a microwave source. We find photon-assisted tunnelling sidebands induced by the
Josephson oscillator, and compare the results with those obtained using an
externally operated microwave source.Comment: 6 pages, 4 figure
Teaching and Assessing Critical Thinking, Nuts and Bolts 1 TEACHING AND ASSESSING CRITICAL THINKING: THE INTERACTION OF STUDENT APPROACHES TO LEARNING AND TEACHING APPROACHES
Abstract This study explored the relationship among student approaches to learning and teaching methods on critical thinking in two business units. Key findings included differences in critical thinking scores between student approaches to learning and some evidence of an interaction between student approaches to learning and critical thinking teach method (immersion vs. infusio
Migratory chondrogenic progenitor cells from repair tissue during the later stages of human osteoarthritis.
Phonon-plasmon coupling in Si doped GaN nanowires
The vibrational properties of silicon doped GaN nanowires with diameters comprised between 40 and 100 nm are studied by Raman spectroscopy through excitation with two different wavelengths: 532 and 405 nm. Excitation at 532 nm does not allow the observation of the coupled phonon-plasmon upper mode for the intentionally doped samples. Yet, excitation at 405 nm results in the appearance of a narrow peak at frequencies close to that of the uncoupled A1(LO) mode for all samples. This behavior points to phonon-plasmon scattering mediated by large phonon wave-vector in these thin and highly doped nanowires
Spin polarization of the L-gap surface states on Au(111)
The electron spin polarization (ESP) of the L-gap surface states on Au(111)
is investigated theoretically by means of first-principles electronic-structure
and photoemission calculations. The surface states show a large spin-orbit
induced in-plane ESP which is perpendicular to the in-plane wavevector, in
close analogy to a two-dimensional electron gas with Rashba spin-orbit
interaction. The surface corrugation leads to a small ESP component normal to
the surface, being not reported so far. The surface-states ESP can be probed
qualitatively and quantitatively by spin- and angle-resolved photoelectron
spectroscopy, provided that the initial-state ESP is retained in the
photoemission process and not obscured by spin-orbit induced polarization
effects. Relativistic photoemission calculations provide detailed information
on what photoemission set-ups allow to conclude from the photoelectron ESP on
that of the surface states.Comment: 22 pages with 8 figure
Effects of nonorthogonality in the time-dependent current through tunnel junctions
A theoretical technique which allows to include contributions from
non-orthogonality of the electron states in the leads connected to a tunneling
junction is derived. The theory is applied to a single barrier tunneling
structure and a simple expression for the time-dependent tunneling current is
derived showing explicit dependence of the overlap. The overlap proves to be
necessary for a better quantitative description of the tunneling current, and
our theory reproduces experimental results substantially better compared to
standard approaches.Comment: 4 pages, 1 table, 1 figur
Investigation of contact deformation and wear characteristics of discrete track recording media
The even semester 2014/2015 Technical Information Engineering University of Semarang (USM) has been running the Competency Based Curriculum (CBC) in the management of learning. Conversions that occur in some subjects at an increase in scheduled meetings in the classroom or in the laboratory. Computer Networks is one of the subjects who experienced a conversion. In the curriculum in 2008, Computer Networking has a number of credits 3. From the 2 credits 3 credits are for credits 1 credits for theory and practical credits. While at the CBC in 2013, Computer Networking has 4 credits, with details of 2 credits 2 credits theory and practicum. As lecture and instructor Computer Network, researchers interested in studying the effect of applying the CBC in 2013 in the subje ct of Computer Network. Does the addition of meeting practical and theoretical material renewal in accordance with the expected competencies?. Researchers tried applying the CBC in 2013 by conducting action research. Implementation of the research was conducted during an ongoing lecture that even semester 2015/2016. The results of the study during the first half of researchers will compare with the achievements that never existed when the old curriculum still in use. The goals of this research is, subjects in the Computer Network has always been one of the subjects that the content of the material and its application in the lab was able to follow the needs of the workforc
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