265 research outputs found
Generation of propagating spin waves from regions of increased dynamic demagnetising field near magnetic antidots
Journal article and accompanying data and mediaThe article appeared in Applied Physics Letters 107, 162401 (2015); doi: 10.1063/1.4933263 and may be found at http://dx.doi.org/10.1063/1.4933263We have used Brillouin Light Scattering and micromagnetic simulations to demonstrate a point-like source of spin waves created by the inherently nonuniform internal magnetic field in the vicinity of an isolated antidot formed in a continuous film of yttrium-iron-garnet. The field nonuniformity ensures that only well-defined regions near the antidot respond in resonance to a continuous excitation of the entire sample with a harmonic microwave field. The resonantly excited parts of the sample then served as reconfigurable sources of spin waves propagating (across the considered sample) in the form of caustic beams. Our findings are relevant to further development of magnonic circuits, in which point-like spin wave stimuli could be required, and as a building block for interpretation of spin wave behavior in magnonic crystals formed by antidot arrays.Engineering and Physical Sciences Research Council (EPSRC)Russian Foundation for Basic ResearchRussian Science FoundationScholarship of the President of Russian Federatio
Field-Controlled Phase-Rectified Magnonic Multiplexer
This is the author accepted manuscript. The final version is available from IEEE via the DOI in this record.The article plus associated .mif files is in ORE: http://hdl.handle.net/10871/18265The mechanism used to alter the features of propagating spin waves is a key component underpinning the functionality of high-frequency magnonic devices. Here, using experiment and micromagnetic simulations, we demonstrate the feasibility of a magnonic multiplexer in which the spin-wave beam is toggled between device output branches by the polarity of a small global bias magnetic field. Due to the anisotropy inherent in the dispersion of magnetostatic spin waves, the phase fronts of the output spin waves are asymmetrically tilted relative to the direction of the beam propagation (group velocity). We show how the phase tilts could be (partly) rectified in the magnonic waveguides of variable widths.This work was supported in part by the U.K. Engineering and Physical Sciences Research Council under Project EP/L019876/1 and Project EP/P505526/1, in part by the Russian Science Foundation under Project 14â19-00760, in part by the Scholarship of the President of Russian Federation (SP-313.2015.5), and in part by the Russian Foundation under Projects 14-07-00273 and 15-37-51253
Magnonic beam splitter: The building block of parallel magnonic circuitry
We demonstrate a magnonic beam splitter that works by inter-converting magnetostatic surface and backward-volume spin waves propagating in orthogonal sections of a T-shaped yttrium iron garnet structure. The inter-conversion is enabled by the overlap of the surface and volume spin wave bands. This overlap results from the demagnetising field induced along the transversely magnetised section(-s) of the structure and the quantization of the transverse wave number of the propagating spin waves (which are therefore better described as waveguide modes). In agreement with numerical micromagnetic simulations, our Brillouin light scattering imaging experiments reveal that, depending on the frequency, the incident fundamental waveguide magnonic modes may also be converted into higher order waveguide modes. The magnonic beam splitter demonstrated here is an important step towards the development of parallel logic circuitry of magnonics.The research leading to these results has received
funding from the Russian Foundation for Basic Research
(Project No. 14-07-00273), the Grant from Russian Science
Foundation (Project No. 14-19-00760), the Scholarship of
the President of Russian Federation (SP-313.2015.5), and
from the Engineering and Physical Sciences Research
Council of the United Kingdom (Project Nos. EP/L019876/1
and EP/P505526/1)
Erratum: Towards graded-index magnonics: Steering spin waves in magnonic networks [Phys. Rev. B 92, 020408(R) (2015)]
This is the final version of the article. Available from the American Physical Societ via the DOI in this record.This is the erratum to 'Towards graded-index magnonics: Steering spin waves in magnonic networks'. Physical Review B 92, 020408(R), 20 July 2015. DOI: https://doi.org/10.1103/PhysRevB.92.020408The article for which this is the erratum is in ORE: http://hdl.handle.net/10871/26167-The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 247556 (NoWaPhen), from the Engineering and Physical Sciences Research Council of the United Kingdom under Projects No. EP/L019876/1 and No. EP/L020696/1, from Russian Science Foundation (Project No. 14-19-00760), and the Scholarship of the President of Russian Federation (SP-313.2015.5)
Spin wave propagation in a uniformly biased curved magnonic waveguide
This is the final version of the article. Available from American Physical Society via the DOI in this record.Using Brillouin light scattering microscopy and micromagnetic simulations, we study the propagation and transformation of magnetostatic spin waves across uniformly biased curved magnonic waveguides. Our results demonstrate that the spin wave transmission through the bend can be enhanced or weakened by modifying the distribution of the inhomogeneous internal magnetic field spanning the structure. Our results open up the possibility of optimally molding the flow of spin waves across networks of magnonic waveguides, thereby representing a step forward in the design and construction of the more complex magnonic circuitry.Structure fabrication and microwave measurements were supported by a grant from the Russian Science Foundation (Grant No. 16-19-10283). This work was also partially supported by the Russian Foundation for Basic Research (Grant No. 16-37-00217), the Scholarship and Grant of the President of RF (Grant No. SP-313.2015.5, MK-5837.2016.9), and the Engineering and Physical Sciences Research Council of the United Kingdom (Projects No. EP/L019876/1 and No. EP/P505526/1)
Precise measurement of the W-boson mass with the CDF II detector
We have measured the W-boson mass MW using data corresponding to 2.2/fb of
integrated luminosity collected in proton-antiproton collisions at 1.96 TeV
with the CDF II detector at the Fermilab Tevatron collider. Samples consisting
of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement
MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most
precise measurement of the W-boson mass to date and significantly exceeds the
precision of all previous measurements combined
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
The azimuthal anisotropy of charged particles in PbPb collisions at
nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS
detector at the LHC over an extended transverse momentum (pt) range up to
approximately 60 GeV. The data cover both the low-pt region associated with
hydrodynamic flow phenomena and the high-pt region where the anisotropies may
reflect the path-length dependence of parton energy loss in the created medium.
The anisotropy parameter (v2) of the particles is extracted by correlating
charged tracks with respect to the event-plane reconstructed by using the
energy deposited in forward-angle calorimeters. For the six bins of collision
centrality studied, spanning the range of 0-60% most-central events, the
observed v2 values are found to first increase with pt, reaching a maximum
around pt = 3 GeV, and then to gradually decrease to almost zero, with the
decline persisting up to at least pt = 40 GeV over the full centrality range
measured.Comment: Replaced with published version. Added journal reference and DO
- âŚ