654 research outputs found
Observation of orbital pumping
Harnessing spin and orbital angular momentum is a fundamental concept in
condensed matter physics, materials science, and quantum-device applications.
In particular, the search for new phenomena that generate a flow of spin
angular momentum, a spin current, has led to the development of spintronics,
advancing the understanding of angular momentum dynamics at the nanoscale. In
contrast to this success, the generation and detection of orbital currents, the
orbital counterpart of spin currents, remains a significant challenge. Here, we
report the observation of orbital pumping, a phenomenon in which magnetization
dynamics pumps an orbital current, a flow of orbital angular momentum. The
orbital pumping is the orbital counterpart of the spin pumping, which is one of
the most versatile and powerful mechanisms for spin-current generation. We show
that the orbital pumping in Ni/Ti bilayers injects an orbital current into the
Ti layer, which is detected through the inverse orbital Hall effect. Our
findings provide a promising approach for generating orbital currents and pave
the way for exploring the physics of orbital transport in solids
Intrinsic Spin Decay Length in Antiferromagnetic Insulator
We report intrinsic spin decay length of an antiferromagnetic insulator. We
found that at an antiferromagnetic/ferromagnetic interface, a spin current
generated by spin pumping is strongly suppressed by two-magnon scattering. By
eliminating the two-magnon contribution, we discovered that the characteristic
length of spin decay in NiO changes by two-orders of magnitude through the
paramagnetic to antiferromagnetic transition. The spin decay length in the
antiferromagnetic state is longer than 100 nm, which is an order of magnitude
longer than previously believed. These results provide a crucial piece of
information for the fundamental understanding of the physics of spin transport
A Study On Automobile Form Design Support Method "AFD-SM"
In this research, by assigning attention to the automobile “form,” details that were previously ambiguous, such as “roundness” and “angle”, are represented numerically. With the aim of measuring the degree of influence of customer sensibility, the “Automobile Design Form Support Method (ADF-SM)”is utilized. Using CAD, the authors have constructed a model of a form-altered automobile to quantitatively evaluate the degree of influence of customer sensitivity. By using this support method, an automobile form is created, which expresses the concept sought by the customer, verifying its effectiveness
Spin-orbit torques originating from bulk and interface in Pt-based structures
We investigated spin-orbit torques in prototypical Pt-based spintronic
devices. We found that, in Pt/Ni and Pt/Fe bilayers, the damping-like torque
efficiency depends on the thickness of the Pt layer. We also found that the
damping-like torque efficiency is almost identical in the Pt/Ni and Pt/Fe
bilayers despite the stronger spin memory loss at the Pt/Fe interface. These
results suggest that although the dominant source of the damping-like torque is
the bulk spin Hall effect in the Pt layer, a sizable damping-like torque is
generated by the interface in the Pt/Fe bilayer due to the stronger interfacial
spin-orbit coupling. In contrast to the damping-like torque, whose magnitude
and sign are almost identical in the Pt/Ni and Pt/Fe bilayers, the field-like
torque strongly depends on the choice of the ferromagnetic layer. The sign of
the field-like torque originating from the bulk spin Hall effect in the Pt
layer is opposite between the Pt/Ni and Pt/Fe bilayers, which can be attributed
to the opposite sign of the imaginary part of the spin-mixing conductance.
These results demonstrate that the spin-orbit torques are quite sensitive to
the electronic structure of the FM layer.Comment: The analysis has been revised based on the ST-FMR signals at higher
frequencie
Lithiation and Delithiation Properties of Si-based Electrodes Pre-coated with a Surface Film Derived from an Ionic-liquid Electrolyte
Ionic-liquid electrolytes can enhance battery performance and safety but are expensive. To reduce the use of ionic-liquid electrolytes, we investigated the charge/discharge properties of Si-based electrodes in an organic-liquid electrolyte, where the electrode surface was pre-coated with a film derived from an ionic-liquid electrolyte. No improvement in the electrode performance was observed compared to that of a nonmodified Si electrode. Once the modified film was broken down, a stable surface film could not be reformed in the organic-liquid electrolyte
Changes in Water network Management since the Meiji Era and Issues Regarding Disaster Prevention at the Foot of Mt. Hira in Shiga Prefecture, Japan
In considering Eco-DRR, it is important to use resources and disaster prevention techniques that make the most of the unique ecosystems of each region. The purpose of this study was to analyze the changes in the water network and its management methods since the Meiji period in Minamikomatsu, Otsu City, located at the foot of Mt. Hira. Based on a literature survey of maps and documents stored in Minamikomatsu, interviews, and field surveys, a water network map was created for each period, and the changes in the management of the water network and issues related to disaster prevention were analyzed. As a result, we were able to confirm the traditional wisdom and techniques of water use and drainage by controlling water intake. On the other hand, the system of water network management has changed with the development of government, agriculture, tourism, and residential areas, and integrated management has become difficult. In addition, changes in the shape and flow of waterways and their disappearance have impeded and fragmented the flow in downstream areas, creating problems for disaster prevention. In the future, it will be important to secure and regenerate the continuity of water networks for watershed basin water control, and to establish a comprehensive water network management system
Substellar Companions to Seven Evolved Intermediate-Mass Stars
We report the detections of substellar companions orbiting around seven
evolved intermediate-mass stars from precise Doppler measurements at Okayama
Astrophysical Observatory. o UMa (G4 II-III) is a giant with a mass of 3.1
M_sun and hosts a planet with minimum mass of m_2sini=4.1 M_J in an orbit with
a period P=1630 d and an eccentricity e=0.13. This is the first planet
candidate (< 13 M_J) ever discovered around stars more massive than 3 M_sun. o
CrB (K0 III) is a 2.1 M_sun giant and has a planet of m_2sini=1.5 M_J in a
187.8 d orbit with e=0.19. This is one of the least massive planets ever
discovered around ~2 M_sun stars. HD 5608 (K0 IV) is an 1.6 M_sun subgiant
hosting a planet of m_2sini=1.4 M_J in a 793 d orbit with e=0.19. The star also
exhibits a linear velocity trend suggesting the existence of an outer, more
massive companion. 75 Cet (G3 III:) is a 2.5 M_sun giant hosting a planet of
m_2sini=3.0 M_J in a 692 d orbit with e=0.12. The star also shows possible
additional periodicity of about 200 d and 1880 d with velocity amplitude of
~7--10 m/s, although these are not significant at this stage. nu Oph (K0 III)
is a 3.0 M_sun giant and has two brown-dwarf companions of m_2sini= 24 M_J and
27 M_J, in orbits with P=530.3 d and 3190 d, and e=0.126 and 0.17,
respectively, which were independently announced by Quirrenbach et al. (2011).
The ratio of the periods is close to 1:6, suggesting that the companions are in
mean motion resonance. We also independently confirmed planets around k CrB (K0
III-IV) and HD 210702 (K1 IV), which had been announced by Johnson et al.
(2008) and Johnson et al. (2007a), respectively. All of the orbital parameters
we obtained are consistent with the previous results.Comment: 21 pages, 14 figures, accepted for publication in PAS
Emotion-reacting fashion design: intelligent garment and accessory recognizing facial expressions
Although mental disorders have emerged as serious social challenges, social stigma, including prejudice and misunderstanding, hinder suitable treatment for the patients. It is crucial to monitor our internal psychological and emotional states to avoid the unconscious progression of mental disorders. This research aims to achieve emotion-reacting garments and accessories, based on a passive and continuous emotion recognition system in real time. First, this study proposes a systematic design for emotion-reacting garments and accessories, which employs emotion estimation based on facial expressions. Next, emotion-reacting fashion design is discussed for intelligent garments and accessories that interact with our bodies and mind. To achieve this system, a functionally extended collar made of transparent polycarbonate material is designed for integration with the digital camera modules. In addition, this study discusses how to create a physical stimulus on emotion-reacting garments and accessories. The intelligent garments and accessories using RGB-LEDs create visual effects that reflect emotions. In terms of audio effects, emotion-related keywords are employed to select the music played in intelligent garments. Finally, prototypes reacting to emotions are show
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