71 research outputs found
Angular dependence of Hall effect and magnetoresistance in SrRuO3−SrIrO3 heterostructures
Perovskite SrRuO is a prototypical itinerant ferromagnet which allows
interface engineering of its electronic and magnetic properties. We report
synthesis and investigation of atomically flat artificial multilayers of
SrRuO with the spin-orbit semimetal SrIrO in combination with
band-structure calculations with a Hubbard term and topological analysis.
They reveal an electronic reconstruction and emergence of flat Ru-4d
bands near the interface, ferromagnetic interlayer coupling and negative
Berry-curvature contribution to the anomalous Hall effect. We analyze the Hall
effect and magnetoresistance measurements as a function of the field angle from
out of plane towards in-plane orientation (either parallel or perpendicular to
the current direction) by a two-channel model. The magnetic easy direction is
tilted by about from the sample normal for low magnetic fields,
rotating towards the out-of-plane direction by increasing fields. Fully
strained epitaxial growth enables a strong anisotropy of magnetoresistance. An
additional Hall effect contribution, not accounted for by the two-channel model
is compatible with stable skyrmions only up to a critical angle of roughly
from the sample normal. Within about from the thin film
plane an additional peak-like contribution to the Hall effect suggests the
formation of a non-trivial spin structure.Comment: to be published in Phys. Rev.
Ultrafast element-resolved magneto-optics using a fiber-laser-driven extreme ultraviolet light source
We present a novel setup to measure the transverse magneto-optical Kerr
effect in the extreme ultraviolet spectral range at exceptionally high
repetition rates based on a fiber laser amplifier system. This affords a very
high and stable flux of extreme ultraviolet light, which we use to measure
element-resolved demagnetization dynamics with unprecedented depth of
information. Furthermore, the setup is equipped with a strong electromagnet and
a cryostat, allowing measurements between 10 and 420 K using magnetic fields up
to 0.86 T. The performance of our setup is demonstrated by a set of
temperature- and time-dependent magnetization measurements showing distinct
element-dependent behavior
Polaronic Emergent Phases in Manganite-based Heterostructures
Transition metal functional oxides, e.g., perovskite manganites, with strong electron, spin and lattice correlations, are well-known for different phase transitions and field-induced colossal effects at the phase transition. Recently, the interfaces between dissimilar perovskites were shown to be a promising concept for the search of emerging phases with novel functionalities. We demonstrate that the properties of manganite films are effectively controlled by low dimensional emerging phases at intrinsic and extrinsic interfaces and appeared as a result of symmetry breaking. The examples include correlated Jahn–Teller polarons in the phase-separated (La1−yPry)0.7Ca0.3MnO3, electron-rich Jahn–Teller-distorted surface or “dead” layer in La0.7Sr0.3MnO3, electric-field-induced healing of “dead” layer as an origin of resistance switching effect, and high-TC ferromagnetic emerging phase at the SrMnO3/LaMnO3 interface in superlattices. These 2D polaronic phases with short-range electron, spin, and lattice reconstructions could be extremely sensitive to external fields, thus, providing a rational explanation of colossal effects in perovskite manganites
New Technique for Posture Identification in Smart Prayer Mat
Smart praying mats are essential to help old and forgetful Muslims perform their religious needs. Due to the binary representation of pressure sensors embedded into the mat for posture identification, existing smart praying systems either use large sensing arrays, thus becoming expensive and bulky, or utilize only a limited number of sensors, minimizing the cost of posture recognition accuracy. This article presents a new technique for detecting human postures and counting posture cycles by a smart mat. Unlike related solutions, the proposed technique identifies postures by voltage levels observed from five sensors only. The technique has been implemented in a prototype smart mat and experimentally evaluated by 30 Islam worshipers. The results show that it provides unobtrusive and robust (100%) recognition of all six postures of the Muslim praying cycle and reliable cycle counting. The implementation is inexpensive, easy to use and quite helpful for users
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