608 research outputs found
Theory of tunneling spectroscopy of normal metal/ferromagnet/spin-triplet superconductor junctions
We study the tunneling conductance of a ballistic normal metal / ferromagnet
/ spin-triplet superconductor junction using the extended
Blonder-Tinkham-Klapwijk formalism as a model for a -axis oriented Au /
SrRuO / SrRuO junction. We compare chiral -wave (CPW) and
helical -wave (HPW) pair potentials, combined with ferromagnet magnetization
directions parallel and perpendicular to the interface. For fixed ,
where is a direction of magnetization in the ferromagnet measured
from the -axis, the tunneling conductance of CPW and HPW clearly show
different voltage dependencies. It is found that the cases where the -vector
is perpendicular to the magnetization direction (CPW with
and HPW with ) are identical. The obtained results serve as a
guide to determine the pairing symmetry of the spin-triplet superconductor
SrRuO.Comment: 12 pages, 7 figures. There is also a supplementary (not uploaded
Match-derived relative pitch area changes the physical and team tactical performance of elite soccer players in small-sided soccer games
Small-sided games (SSGs) are used in training sessions to prepare for full-sized matches. For the same number of players, smaller pitch sizes result in decreased physical performance and shorter interpersonal distances. A relative pitch area derived from the full-sized match results in larger pitch sizes and this may increase the fit between SSGs and full-sized matches. This study aimed to investigate SSGs with a traditional small pitch and a match-derived relative pitch area in youth elite soccer players. Four age categories (under-13, under-15, under-17 and under-19) played 4 vs. 4 plus goalkeepers on a small (40x30m, 120m(2) relative pitch area) and large pitch (68x47m, 320m(2) relative pitch area). The number of games per age category ranged 15-30. Positional data (LPM-system) were collected to determine physical (total distance covered, high intensity distance and number of sprints) and team tactical (inter-team distance, LPW-ratio, surface area, stretch indices, goalkeeper-defender distance) performance measures and tactical variability. On a large pitch, physical performance significantly increased, inter-team and intra-team distances were significantly larger and tactical variability of intra-team distance measures significantly increased. The match-derived relative pitch area is an important training manipulation and leads to changes in physical and tactical performance 4 vs. 4 plus goalkeepers.</p
Tunable critical field in Rashba superconductor thin-films
The upper critical field in type II superconductors is limited by the Pauli
paramagnetic limit. In superconductors with strong Rashba spin-orbit coupling
this limit can be overcome by forming a helical state. Here we quantitatively
study the magnetic field-temperature phase diagram of finite-size
superconductors with Rashba spin-orbit coupling. We discuss the effect of
finite size and shape anisotropy. We demonstrate that the critical field is
controllable by intrinsic parameters such as spin-orbit coupling strength and
tunable parameters such as sample geometry and applied field direction. Our
study opens new avenues for the design of superconducting spin-valves.Comment: 5 pages, 4 figures, supplemental material
Comparison of Accu Chek Inform II point-of-care test blood glucose meter with Hexokinase Plasma method for a diabetes mellitus population during surgery under general anesthesia
Purpose Blood glucose (BG) concentrations of patients with diabetes mellitus (DM) are monitored during surgery to prevent hypo- and hyperglycemia. Access to point-of-care test (POCT) glucose meters at an operating room will usually provide monitoring at shorter intervals and may improve glycemic control. However, these meters are not validated for patients under general anesthesia. Methods This cross-sectional study included 75 arterial BG measurements from 75 patients (71 with DM, mostly insulin dependent) who underwent elective non-cardiac surgery under general anesthesia. Arterial blood samples were taken at least 60 minutes after induction. One drop of blood was used for Accu Chek Inform II (ACI II) POCT BG meter and the residual blood was sent to the clinical laboratory for a Hexokinase Plasma reference method. A Bland-Altman plot was used to visualize the differences between both methods, and correlation was assessed using the intra-class correlation coefficient (ICC). Results The results showed an estimated mean difference of 0.8 mmol/L between ACI II and the reference method, with limits of agreement equal to -0.6 and 2.2 mmol/L. In general, the reference method produced higher values than ACI II. ICC was 0.955 (95% CI 0.634-0.986), P < 0.001, and concordance correlation coefficient (CCC) was 0.955 (95% CI 0.933-0.970). Conclusion Arterial BG measurements during surgery in patients with DM under general anesthesia using POCT BG meter are in general lower than laboratory measurements, but the ICC and CCC show a clinically acceptable correlation. We conclude that POCT measurements conducted on arterial specimens using the ACI II provide sufficiently accurate results for glucose measurement during surgery under general anesthesia.</p
Multiple Andreev reflections in two-dimensional Josephson junctions with broken time-reversal symmetry
Andreev bound states (ABS) occur in Josephson junctions when the total phase
of the Andreev and normal reflections is a multiple of . In ballistic
junctions with an applied voltage bias, a quasi-particle undergoes multiple
Andreev reflections before entering the leads, resulting in peaks in the
current-voltage curve. Here we present a general model for Josephson
junctions with spin-active interlayers i.e., magnetic or topological materials
with broken time-reversal symmetry. We investigate how ABS change the peak
positions and shape of , which becomes asymmetric for a single incident
angle. We show how the angle-resolved curve becomes a spectroscopic tool
for the chirality and degeneracy of ABS.Comment: 5 pages, 3 figure
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