34,156 research outputs found
Spin reorientation transition in the incommensurate stripe-ordered phase of La3/2Sr1/2NiO4
The spin ordering of La3/2Sr1/2NiO4 was investigated by magnetization
measurements, and by unpolarized- and polarized-neutron diffraction. Spin
ordering with an incommensurability epsilon ~ 0.445 is observed below T_so ~ 80
K. On cooling, a spin reorientation is observed at 57 +/- 1 K, with the spin
axes rotating from 52 +/- 4 degrees to 78 +/- 3 degrees. This is the first time
a spin reorientation has been observed in a La2-xSrxNiO4+delta compound having
incommensurate stripe order.Comment: REVTex 4. 4 pages including 4 figures. Minor changes to text.
Accepted to be published in Physical Review
FAMILY JUSTICE AND FAMILY VALUES ACCORDING TO LORD DENNING
FAMILY JUSTICE AND FAMILY VALUES ACCORDING TO LORD DENNIN
Geometric Aspects of Composite Pulses
Unitary operations acting on a quantum system must be robust against
systematic errors in control parameters for reliable quantum computing.
Composite pulse technique in nuclear magnetic resonance (NMR) realises such a
robust operation by employing a sequence of possibly poor quality pulses. In
this article, we demonstrate that two kinds of composite pulses, one
compensates for a pulse length error in a one-qubit system and the other
compensates for a J-coupling error in a twoqubit system, have vanishing
dynamical phase and thereby can be seen as geometric quantum gates, which
implement unitary gates by the holonomy associated with dynamics of cyclic
vectors defined in the text.Comment: 20 pages, 4 figures. Accepted for publication in Philosophical
Transactions of the Royal Society
The intrinsic strangeness and charm of the nucleon using improved staggered fermions
We calculate the intrinsic strangeness of the nucleon, - ,
using the MILC library of improved staggered gauge configurations using the
Asqtad and HISQ actions. Additionally, we present a preliminary calculation of
the intrinsic charm of the nucleon using the HISQ action with dynamical charm.
The calculation is done with a method which incorporates features of both
commonly-used methods, the direct evaluation of the three-point function and
the application of the Feynman- Hellman theorem. We present an improvement on
this method that further reduces the statistical error, and check the result
from this hybrid method against the other two methods and find that they are
consistent. The values for and found here, together with
perturbative results for heavy quarks, show that dark matter scattering through
Higgs-like exchange receives roughly equal contributions from all heavy quark
flavors.Comment: 17 pages, 14 figure
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Correlation of individual differences in audiovisual asynchrony across stimuli and tasks: new constraints on Temporal Renormalization theory
Sight and sound are out of synch in different people by different amounts for different tasks. But surprisingly, different concurrent measures of perceptual asynchrony correlate negatively (Freeman, Ipser et al, 2013. Cortex 49, 2875ā2887): thus if vision subjectively leads audition in one individual, the same individual might show a visual lag in other measures of audiovisual integration (e.g. McGurk illusion, Stream-Bounce illusion).
This curious negative correlation was first observed between explicit temporal order judgements and implicit phoneme identification tasks, performed concurrently as a dual task, using incongruent McGurk stimuli. Here we used a new set of different of explicit and implicit tasks and congruent stimuli, to test whether this negative correlation persists across testing sessions, and whether it might be an artefact of using specific incongruent stimuli. None of these manipulations eliminated the negative correlation between explicit and implicit measures. This supports the generalisability and validity of the phenomenon, and offers new theoretical insights into its explanation.
Our previously proposed ātemporal renormalizationā theory assumes that the timings of sensory events registered within the brainās different multimodal sub-networks are each perceived relative to a representation of the typical average timing of such events across the wider network. Our new data suggest that this representation is stable and generic, rather than dependent on specific stimuli or task contexts, and that it may be acquired through experience with a variety of simultaneous stimuli. Our results also add further evidence that speech comprehension may be improved in some individuals by artificially delaying voices relative to lip-movements
Narrative transformation among military personnel on an adventurous training and sport course.
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