Read by QxMD icon Read


J Cowley, C Thornton, C Arran, R J Shalloo, L Corner, G Cheung, C D Gregory, S P D Mangles, N H Matlis, D R Symes, R Walczak, S M Hooker
We demonstrate experimentally the resonant excitation of plasma waves by trains of laser pulses. We also take an important first step to achieving an energy recovery plasma accelerator by showing that a plasma wave can be damped by an out-of-resonance trailing laser pulse. The measured laser wakefields are found to be in excellent agreement with analytical and numerical models of wakefield excitation in the linear regime. Our results indicate a promising direction for achieving highly controlled, GeV-scale laser-plasma accelerators operating at multikilohertz repetition rates...
July 28, 2017: Physical Review Letters
Andrew S Darmawan, David Poulin
The surface code is a many-body quantum system, and simulating it in generic conditions is computationally hard. While the surface code is believed to have a high threshold, the numerical simulations used to establish this threshold are based on simplified noise models. We present a tensor-network algorithm for simulating error correction with the surface code under arbitrary local noise. We use this algorithm to study the threshold and the subthreshold behavior of the amplitude damping and systematic rotation channels...
July 28, 2017: Physical Review Letters
V Shiltsev, Y Alexahin, A Burov, A Valishev
Modern and future particle accelerators employ increasingly higher intensity and brighter beams of charged particles and become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, beam feedback dampers, and use of chromatic effects, become less effective and insufficient. We show that, in contrast, Lorentz forces of a low-energy, magnetically stabilized electron beam, or "electron lens," easily introduce transverse nonlinear focusing sufficient for Landau damping of transverse beam instabilities in accelerators...
September 29, 2017: Physical Review Letters
Xun Jia, Shuyuan Zhang, Raman Sankar, Fang-Cheng Chou, Weihua Wang, K Kempa, E W Plummer, Jiandi Zhang, Xuetao Zhu, Jiandong Guo
Plasmons, the collective excitations of electrons in the bulk or at the surface, play an important role in the properties of materials, and have generated the field of "plasmonics." We report the observation of a highly unusual acoustic plasmon mode on the surface of a three-dimensional topological insulator (TI) Bi_{2}Se_{3}, using momentum resolved inelastic electron scattering. In sharp contrast to ordinary plasmon modes, this mode exhibits almost linear dispersion into the second Brillouin zone and remains prominent with remarkably weak damping not seen in any other systems...
September 29, 2017: Physical Review Letters
Tiago A Morgado, Mário G Silveirinha
We theoretically demonstrate that a system formed by two coupled graphene sheets enables a negative damping regime wherein graphene plasmons are pumped by a direct current. This effect is triggered by electrons drifting through one of the graphene sheets and leads to wave instabilities and a spontaneous light emission (spasing) in the midinfrared range. It is shown that there is a deep link between the drift-induced instabilities and wave instabilities in moving media, as both result from the hybridization of oscillators with oppositely signed frequencies...
September 29, 2017: Physical Review Letters
Zhe Wang, Yuanhua Yu, Zhanjiang Yu, Qimeng Chen
With the increasing demand for coagulation POCT for patients in the surgery department or the ICU, rapid coagulation testing techniques and methods have drawn widespread attention from scholars and businessmen. This paper proposes the use of electromagnetic induction sensor probe for detection of dynamic process causing changes in the blood viscosity and density before and after coagulation based on the damped vibration principle, in order to evaluate the coagulation status. Utilizing the dynamic principle, the differential equation of vibration system comprising elastic support and electromagnetic induction device is established through sensor dynamic modeling...
January 16, 2018: Australasian Physical & Engineering Sciences in Medicine
Quoc Vo, Haibin Su, Tuan Tran
Droplet spreading on substrates by electrowetting exhibits either of the two transient behaviours: one characterised by contact line oscillation, and the other one by slow spreading dynamics. The transition between these behaviours remains elusive due to the current limited understanding of the spreading dynamics on the hydrodynamical and electrical properties of electrowetting systems. To understand this transition we propose a model capturing the transition's occurrence based on both the hydrodynamical and electrical parameters...
January 16, 2018: Scientific Reports
Y T Fanchiang, K H M Chen, C C Tseng, C C Chen, C K Cheng, S R Yang, C N Wu, S F Lee, M Hong, J Kwo
Harnessing the spin-momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi2Se3/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi2Se3 film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG...
January 15, 2018: Nature Communications
Taimoor Ashraf Ashraf, Meelad Ranaiefar, Sumit Khatri, Jamshid Kavosi, Frank Gardea, Bryan Glaz, Mohammad Naraghi
Safe operation and health of structures relies on their ability to effectively dissipate undesired vibrations, which could otherwise significantly reduce the life-time of a structure due to fatigue loads or large deformations. To address this issue, nanoscale fillers, such as carbon nanotubes (CNTs), have been utilized to dissipate mechanical energy in polymer-based nanocomposites through filler-matrix interfacial friction by benefitting from their large interface area with the matrix. In this manuscript, for the first time, we experimentally investigate the effect of CNT alignment with respect to reach other and their orientation with respect to the loading direction on vibrational damping in nanocomposites...
January 15, 2018: Nanotechnology
Diana Madsen, Ove Christiansen, Carolin König
We extend the fragmentation-based double incremental expansion in FALCON coordinates (DIF) and its linear-scaling analogue [C. König and O. Christiansen, J. Chem. Phys., 2016, 145, 064105] to dipole surfaces. Thereby, we enable the calculation of intensities in vibrational absorption spectra from these cost-efficient property surfaces. We validate the obtained potential energy and dipole surfaces by vibrational spectra calculations employing damped response theory for correlated vibrational coupled cluster wave functions...
January 15, 2018: Physical Chemistry Chemical Physics: PCCP
Stephen M Goldman, Beth E P Henderson, Thomas J Walters, Benjamin T Corona
Minced muscle autografting mediates de novo myofiber regeneration and promotes partial recovery of neuromuscular strength after volumetric muscle loss injury (VML). A major limitation of this approach is the availability of sufficient donor tissue for the treatment of relatively large VMLs without inducing donor site morbidity. This study evaluated a laminin-111 supplemented hyaluronic acid based hydrogel (HA+LMN) as a putative myoconductive scaffolding to be co-delivered with minced muscle grafts. In a rat tibialis anterior muscle VML model, delivery of a reduced dose of minced muscle graft (50% of VML defect) within HA+LMN resulted in a 42% improvement of peak tetanic torque production over unrepaired VML affected limbs...
2018: PloS One
Inkyung Kang, Mary Y Chang, Thomas N Wight, Charles W Frevert
Proteoglycans (PGs) are complex, multifaceted molecules that participate in diverse interactions vital for physiological and pathological processes. As structural components, they provide a scaffold for cells and structural organization that helps define tissue architecture. Through interactions with water, PGs enable molecular and cellular movement through tissues. Through selective ionic interactions with growth factors, chemokines, cytokines, and proteases, PGs facilitate the ability of these soluble ligands to regulate intracellular signaling events and to influence the inflammatory response...
January 1, 2018: Journal of Histochemistry and Cytochemistry: Official Journal of the Histochemistry Society
K A Matveev, A V Andreev
We study sound in Galilean invariant systems of one-dimensional fermions. At low temperatures, we find a broad range of frequencies in which in addition to the waves of density there is a second sound corresponding to the ballistic propagation of heat in the system. The damping of the second sound mode is weak, provided the frequency is large compared to a relaxation rate that is exponentially small at low temperatures. At lower frequencies, the second sound mode is damped, and the propagation of heat is diffusive...
December 29, 2017: Physical Review Letters
Takahiro Moriyama, Michinari Kamiya, Kent Oda, Kensho Tanaka, Kab-Jin Kim, Teruo Ono
Spin interaction in antiferromagnetic materials is of central interest in the recently emerging antiferromagnetic spintronics. In this Letter, we explore the spin current interaction in antiferromagnetic FeMn by the spin pumping effect. Exchange biased FeNi/FeMn films, in which the Néel vector can be presumably controlled via the exchange spring effect, are employed to investigate the damping enhancement depending on the relative orientation between the Néel vector and the polarization of the pumped spin current...
December 29, 2017: Physical Review Letters
Yvan Castin, Alice Sinatra, Hadrien Kurkjian
Liquid helium and spin-1/2 cold-atom Fermi gases both exhibit in their superfluid phase two distinct types of excitations, gapless phonons and gapped rotons or fermionic pair-breaking excitations. In the long wavelength limit, revising and extending the theory of Landau and Khalatnikov initially developed for helium [Zh. Exp. Teor. Fiz. 19, 637 (1949)], we obtain universal expressions for three- and four-body couplings among these two types of excitations. We calculate the corresponding phonon damping rates at low temperature and compare them to those of a pure phononic origin in high-pressure liquid helium and in strongly interacting Fermi gases, paving the way to experimental observations...
December 29, 2017: Physical Review Letters
Minghong Tang, Bingcheng Zhao, Weihua Zhu, Zhendong Zhu, Qingyuan Jin, Zongzhi Zhang
Dynamic magnetic properties in perpendicularly exchange-coupled [Co/Ni]5/Cu(tCu=0-2 nm)/TbCo structures show strong dependences on the interfacial AFM strength Jex controlled by the Cu interlayer thickness. The precession frequency f and effective damping constant αeff of [Co/Ni]5 multilayer differs distinctly for parallel (P) and antiparallel (AP) magnetization orientation states. For samples with a thin tCu, f of AP state is apparently higher while αeff is lower than in P state, owing to the unidirectional exchange bias effect (HEB) from the TbCo layer...
January 12, 2018: ACS Applied Materials & Interfaces
Feng Wang, Hayk Harutyunyan
Plasmonic nanoantennas and metamaterials concentrate optical energy into nanometric volumes strongly enhancing the light-matter interaction. This makes them promising platforms for optical sensing, nonlinear effects and quantum optics. However, absorption losses and radiative damping result in broad, low quality factor (Q) resonances of plasmonic systems that significantly limit their performance. Here, we develop a hybrid plasmonic/dielectric metasurface that can simultaneously achieve high Q and large field enhancement values in the near infrared by forming a hybridized mode between the nanoantennas' plasmonic mode and the photonic waveguide mode of Si device layer...
January 8, 2018: Optics Express
Lyu-Chih Lin, Chih-Ying Chen, Heming Huang, Dejan Arsenijević, Dieter Bimberg, Frédéric Grillot, Fan-Yi Lin
We experimentally compare the dynamics of InAs/GaAs quantum dot lasers under optical feedback emitting exclusively on ground states (GSs) or excited states (ESs). By varying the feedback parameters and putting focus either on their short or long cavity regions, various periodic and chaotic oscillatory states are found. The GS laser is shown to be more resistant to feedback, benefiting from its strong relaxation oscillation damping. In contrast, the ES laser can easily be driven into complex dynamics. While the GS laser is of importance for the development of isolator-free transmitters, the ES laser is essential for applications taking advantages of chaos...
January 15, 2018: Optics Letters
Yuzhi Shi, Sha Xiong, Lip Ket Chin, Jingbo Zhang, Wee Ser, Jiuhui Wu, Tianning Chen, Zhenchuan Yang, Yilong Hao, Bo Liedberg, Peng Huat Yap, Din Ping Tsai, Cheng-Wei Qiu, Ai Qun Liu
The past two decades have witnessed the revolutionary development of optical trapping of nanoparticles, most of which deal with trapping stiffness larger than 10-8 N/m. In this conventional regime, however, it remains a formidable challenge to sort out sub-50-nm nanoparticles with single-nanometer precision, isolating us from a rich flatland with advanced applications of micromanipulation. With an insightfully established roadmap of damping, the synchronization between optical force and flow drag force can be coordinated to attempt the loosely overdamped realm (stiffness, 10-10 to 10-8 N/m), which has been challenging...
January 2018: Science Advances
Ju-Hyeong Park, Sook Ja Cho, Sandra K White, Jean M Cox-Ganser
There is limited information on the natural history of building occupants' health in relation to attempts to remediate moisture damage. We examined changes in respiratory and non-respiratory symptoms in 1,175 office building occupants over seven years with multiple remediation attempts. During each of four surveys, we categorized participants using a severity score: 0 = asymptomatic; 1 = mild, symptomatic in the last 12 months, but not frequently in the last 4 weeks; 2 = severe, symptomatic at least once weekly in the last 4 weeks...
2018: PloS One
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"