Read by QxMD icon Read


Ronald L Cappelletti, Terrence Jach, John Vinson
It has been shown that single-particle wave functions, of both photons and electrons, can be created with a phase vortex, i.e., an intrinsic orbital angular momentum (OAM). A recent experiment has claimed similar success using neutrons [C. W. Clark et al., Nature, 525, 504 (2015)NATUAS0028-083610.1038/nature15265]. We show that their results are insufficient to unambiguously demonstrate OAM, and they can be fully explained as phase contrast interference patterns. Furthermore, given the small transverse coherence length of the neutrons in the original experiment, the probability that any neutron was placed in an OAM state is vanishingly small...
March 2, 2018: Physical Review Letters
H Wu, L Huang, C Fang, B S Yang, C H Wan, G Q Yu, J F Feng, H X Wei, X F Han
The key physics of the spin valve involves spin-polarized conduction electrons propagating between two magnetic layers such that the device conductance is controlled by the relative magnetization orientation of two magnetic layers. Here, we report the effect of a magnon valve which is made of two ferromagnetic insulators (YIG) separated by a nonmagnetic spacer layer (Au). When a thermal gradient is applied perpendicular to the layers, the inverse spin Hall voltage output detected by a Pt bar placed on top of the magnon valve depends on the relative orientation of the magnetization of two YIG layers, indicating the magnon current induced by the spin Seebeck effect at one layer affects the magnon current in the other layer separated by Au...
March 2, 2018: Physical Review Letters
Muralidhar Pai K, R Chandrasekhar Naidu, A Raja, Y S Rai, Niranjan Kumar, Anand Kini, Santhosh Joseph, Vinod Hegde, H S Ballal, Ramoorthi Rao, Saroja V Sharma, Vinay Kumar Valakatte
Craniopagus twins are conjoined twins fused at the cranium. This is the rarest anomaly seen in conjoined twins and craniopagus twins account for 2- 6% of conjoined twins. Conjoined twins are also extremely rare, with the anomaly seen in about 10-20 subjects per billion births. A female preponderance has been noted. Craniopagus twins can be classified into complete or partial, depending on whether or not they have shared dural venous sinuses. They can be further classified into angular or total depending on the alignment of the inter-twin longitudinal axis...
March 2018: Neurology India
Hari Babu Vasili, Matheus Gamino, Jaume Gazquez, Florencio Sanchez, Manuel Valvidares, Pierluigi Gargiani, Eric Pellegrin, Josep Fontcuberta
Pure spin currents hold promises for an energy-friendlier spintronics. They can be generated by a flow of charge along a non-magnetic metal having a large spin-orbit coupling. It produces a spin accumulation at its surfaces, controllable by the magnetization of an adjacent ferromagnetic layer. Paramagnetic metals typically used are close to a ferromagnetic instability and thus magnetic proximity effects can contribute to the observed angular-dependent magnetoresistance (ADMR). As interface phenomena govern the spin conductance across the metal/ferromagnetic-insulator heterostructures, unraveling these distinct contributions is pivotal to full understanding of spin current conductance...
March 16, 2018: ACS Applied Materials & Interfaces
Adam S Lowet, Chaz Firestone, Brian J Scholl
An intrinsic part of seeing objects is seeing how similar or different they are relative to one another. This experience requires that objects be mentally represented in a common format over which such comparisons can be carried out. What is that representational format? Objects could be compared in terms of their superficial features (e.g., degree of pixel-by-pixel overlap), but a more intriguing possibility is that they are compared on the basis of a deeper structure. One especially promising candidate that has enjoyed success in the computer vision literature is the shape skeleton-a geometric transformation that represents objects according to their inferred underlying organization...
March 15, 2018: Attention, Perception & Psychophysics
Kazuhisa Matsui, Takashi Tachibana, Katsuya Nobuhara, Yasushi Uchiyama
BACKGROUND: The glenohumeral joint is subjected to opposing forces when the direction of shoulder motion is changed, accelerating and decelerating to make the movements. The influence of motion velocity or acceleration on translation of the humeral head has not been evaluated although direction and distance of humeral head translation has been analyzed in real time in normal shoulders. We hypothesized that, in a normal shoulder, the humeral head does not deviate significantly or suddenly during active shoulder rotation regardless of motion velocity...
March 15, 2018: Journal of Experimental Orthopaedics
Yoichi Kaizu, Hideomi Watanabe, Takehiko Yamaji
[Purpose] The purpose of this study was to provide information regarding the knowledge of mechanical principles related to the load applied to the shoulder and elbow during the pitching motion. [Subjects and Methods] The three-dimensional kinematics of body segments were measured in 19 amateur baseball players with a VICON motion capture system. The correlation between maximum shoulder internal torque, maximum elbow varus torque, and simultaneous kinematic parameters including joint angular acceleration and ball acceleration was investigated...
February 2018: Journal of Physical Therapy Science
Wojciech Rzadkowski, Mikhail Lemeshko
Recently it was shown that a molecule rotating in a quantum solvent can be described in terms of the "angulon" quasiparticle [M. Lemeshko, Phys. Rev. Lett. 118, 095301 (2017)]. Here we extend the angulon theory to the case of molecules possessing an additional spin-1/2 degree of freedom and study the behavior of the system in the presence of a static magnetic field. We show that exchange of angular momentum between the molecule and the solvent can be altered by the field, even though the solvent itself is non-magnetic...
March 14, 2018: Journal of Chemical Physics
Sebastian Trippel, Joss Wiese, Terry Mullins, Jochen Küpper
Strong quasi-adiabatic laser alignment of the indole-water-dimer clusters, an amino-acid chromophore bound to a single water molecule through a hydrogen bond, was experimentally realized. The alignment was visualized through ion and electron imaging following strong-field ionization. Molecular-frame photoelectron angular distributions showed a clear suppression of the electron yield in the plane of the ionizing laser's polarization, which was analyzed as strong alignment of the molecular cluster with ⟨cos2 θ2D ⟩ ≥ 0...
March 14, 2018: Journal of Chemical Physics
Rashmi Panda, N B Puhan, Aparna Rao, Debananda Padhy, Ganapati Panda
Retinal nerve fiber layer defect (RNFLD) provides an early objective evidence of structural changes in glaucoma. RNFLD detection is currently carried out using imaging modalities like OCT and GDx which are expensive for routine practice. In this regard, we propose a novel automatic method for RNFLD detection and angular width quantification using cost effective redfree fundus images to be practically useful for computer-assisted glaucoma risk assessment. After blood vessel inpainting and CLAHE based contrast enhancement, the initial boundary pixels are identified by local minima analysis of the 1-D intensity profiles on concentric circles...
March 6, 2018: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Shimao Li, Yunhong Ding, Xiaowei Guan, Heyun Tan, Zhichao Nong, Lin Wang, Lin Liu, Lidan Zhou, Chunchuan Yang, Kresten Yvind, Leif Katsuo Oxenløwe, Siyuan Yu, Xinlun Cai
Photonic integrated devices that emit vortex beam carrying orbital angular momentum are becoming key components for multiple applications. Here we propose and demonstrate a high-efficiency vortex beam emitter based on a silicon micro-ring resonator integrated with a metal mirror. Such a compact emitter is capable of generating vortex beams with a high efficiency and small divergence angle. Vector vortex beams of various topological charges are selectively generated by the emitter at different wavelengths with an emission efficiency of up to 37%...
March 15, 2018: Optics Letters
Lu Cai, Kaikai Du, Yurui Qu, Hao Luo, Meiyan Pan, Min Qiu, Qiang Li
Polar crystals can enable strong light-matter interaction at an infrared regime and provide many practical applications including thermal emission. However, the dynamic control of thermal emission based on polar crystals remains elusive as the lattice vibrations are solely determined by the crystal structure. Here, a nonvolatile tunable midinfrared thermal emitter enabled by a phase-changing film Ge2 Sb2 Te5 on silicon carbide polar crystal is demonstrated. By controlling the state of Ge2 Sb2 Te5 from an amorphous to a crystalline state, the emissivity of the thermal emitter is tuned from a low value to near unity with a maximum change in peak emissivity exceeding 10 dB over the Reststrahlen band of SiC (11...
March 15, 2018: Optics Letters
Xiao Ming Zhang, Qiang Zhang, Shang Jie Zeng, Zhen Zhen Liu, Jun-Jun Xiao
High-index dielectric nanoantennas have become an emerging branch of optical nanoantennas, essentially due to their low loss. These types of nanoantennas can achieve both forward and backward unidirectional scattering, enabled by electric dipole and magnetic dipole interaction. Here, we show that the scattering directionality can be further enhanced if higher-order moments are properly balanced and reach the generalized Kerker condition at two different wavelengths in an all-dielectric hollow nanodisk. Moreover, putting the nanodisks in an array of transverse configuration can enhance the unidirectionality to be needle-like, with the main lobe angular beam width α<15°...
March 15, 2018: Optics Letters
Zengkai Shao, Jiangbo Zhu, Yanfeng Zhang, Yujie Chen, Siyuan Yu
Cylindrical vector vortex (CVV) beams, complex light fields that exhibit a vector nature and carry quantized orbital angular momentum (OAM) states, have been widely investigated due to their rich applications. Current technologies to generate CVV beams using individual polarization and spatial phase manipulations suffer from bulky size and low configurability. In this Letter, we propose and experimentally demonstrate an approach to generate CVV beams with a single integrated device based on a silicon nitride microring resonator and embedded top-gratings...
March 15, 2018: Optics Letters
Marco Ornigotti
In this work, I present a full analytical theory for the Goos-Hänchen and Imbert-Fedorov shifts experienced by an Airy beam impinging on a dielectric surface. In particular, I will show how the decay parameter α associated with finite energy Airy beams is responsible for the occurrence of giant angular shifts. A comparison with the case of Gaussian beams is also discussed.
March 15, 2018: Optics Letters
Meng Han, Peipei Ge, Yun Shao, Qihuang Gong, Yunquan Liu
We employ attosecond angular streaking with photoelectron interferometric metrology to reveal electron sub-Coulomb-barrier dynamics. We use a weak perturbative corotating circularly polarized field (800 nm) to probe the strong-field ionization by an intense circularly polarized field (400 nm). In this double-pointer attoclock photoelectron interferometry, we introduce a spatially rotating temporal Young's two-slit interferometer, in which the oppositely modulated wave packets originating from consecutive laser cycles are dynamically prepared and interfered...
February 16, 2018: Physical Review Letters
Cyprian Lewandowski, L S Levitov
In Dirac materials linear band dispersion blocks momentum-conserving interband transitions, creating a bottleneck for electron-hole pair production and carrier multiplication in the photoexcitation cascade. Here we show that the decays are unblocked and the bottleneck is relieved by subtle many-body effects involving multiple off-shell e-h pairs. The decays result from a collective behavior due to simultaneous emission of many soft pairs. We discuss characteristic signatures of the off-shell pathways, in particular the sharp angular distribution of secondary carriers, resembling relativistic jets in high-energy physics...
February 16, 2018: Physical Review Letters
Xiaoou Zhang, Wen-Yu Shan, Di Xiao
We show that the exciton optical selection rule in gapped chiral fermion systems is governed by their winding number w, a topological quantity of the Bloch bands. Specifically, in a C_{N}-invariant chiral fermion system, the angular momentum of bright exciton states is given by w±1+nN with n being an integer. We demonstrate our theory by proposing two chiral fermion systems capable of hosting dark s-like excitons: gapped surface states of a topological crystalline insulator with C_{4} rotational symmetry and biased 3R-stacked MoS_{2} bilayers...
February 16, 2018: Physical Review Letters
Frank Jülicher, Stephan W Grill, Guillaume Salbreux
We review the general hydrodynamic theory of active soft materials that is motivated in partic- ular by biological matter. We present basic concepts of irreversible thermodynamics of spatially extended multicomponent active systems. Starting from the rate of entropy production, we iden- tify conjugate thermodynamic fluxes and forces and present generic constitutive equations of polar active fluids and active gels. We also discuss angular momentum conservation which plays a role in the the physics of active chiral gels...
March 15, 2018: Reports on Progress in Physics
Yu-Jie Dai, Xin Zhang, Yang Yang, Hai-Yan Nan, Ying Yu, Qian Sun, Lin-Feng Yan, Bo Hu, Jin Zhang, Zi-Yu Qiu, Yi Gao, Guang-Bin Cui, Bi-Liang Chen, Wen Wang
BACKGROUND: The incidence of pain disorders in women is higher than in men, making gender differences in pain a research focus. The human insular cortex is an important brain hub structure for pain processing and is divided into several subdivisions, serving different functions in pain perception. Here we aimed to examine the gender differences of the functional connectivities (FCs) between the twelve insular subdivisions and selected pain-related brain structures in healthy adults. METHODS: Twenty-six healthy males and 11 age-matched healthy females were recruited in this cross-sectional study...
March 14, 2018: Journal of Headache and Pain
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"