12,714 research outputs found
Anomalous Nernst and Hall effects in magnetized platinum and palladium
We study the anomalous Nernst effect (ANE) and anomalous Hall effect (AHE) in
proximity-induced ferromagnetic palladium and platinum which is widely used in
spintronics, within the Berry phase formalism based on the relativistic band
structure calculations. We find that both the anomalous Hall ()
and Nernst () conductivities can be related to the spin Hall
conductivity () and band exchange-splitting () by
relations and
,
respectively. In particular, these relations would predict that the
in the magnetized Pt (Pd) would be positive (negative) since
the is positive (negative). Furthermore, both
and are approximately proportional to the
induced spin magnetic moment () because the is a linear
function of . Using the reported in the magnetized Pt and Pd, we
predict that the intrinsic anomalous Nernst conductivity (ANC) in the magnetic
platinum and palladium would be gigantic, being up to ten times larger than,
e.g., iron, while the intrinsic anomalous Hall conductivity (AHC) would also be
significant.Comment: Accepted for publication in the Physical Review
Context effects in inflation surveys: The influence of additional information and prior questions
Context effects are known to affect responses to surveys. We report effects of information and task contexts in surveys of inflation expectations. Information context refers to contextual information about earlier inflation rates or other economic indicators. Task context refers to judgement tasks performed prior to the inflation judgement task under consideration. In three experiments, we show that contextual information improves judgement accuracy. As this information is given in expert, but not in lay surveys, its provision may partly explain why expert judgements are superior to those of lay people. In both expert and lay surveys, respondents make inflation judgements in the context of already having made other inflation judgements. We show that when different groups of people make inflation judgements either for the current or for the upcoming year, their judgements do not differ. However, when the same people make judgements for both the current and the upcoming years, the latter are significantly higher than the former, perhaps because people expect inflation to increase over time
Are lay expectations of inflation based on recall of specific prices? If so, how and under what conditions?
In 2019 when inflation was low and stable, we compared people's direct estimates of inflation with indirect estimates obtained by averaging their estimates of price changes in all 12 product categories on which the consumer price index is based. Indirect estimates were much higher than direct ones and the two types of estimate were uncorrelated. This is consistent with a price-free model in which direct estimates are not based on recall of prices but are determined by other information such as media reports. In May 2022 when inflation was high, expected to rise in the short-term, but highly unpredictable in the longer term, we found that direct and indirect estimates were very similar and highly correlated. This is consistent with a price-recall model in which a representative set of prices is used to estimate overall inflation. Finally, in September 2022 when inflation was fairly stable except for certain product categories (food) where prices were rising rapidly, we found that results were consistent with a third approach, the price-salience model; overall estimates of inflation are selectively influenced by price rises in those product categories where they are particularly high. People's strategy for estimating inflation appears adapted to the prevailing inflation environment
Carrier-envelope phase dependence in single-cycle laser pulse propagation with the inclusion of counter-rotating terms
We focus on the propagation properties of a single-cycle laser pulse through
a two-level medium by numerically solving the full-wave Maxwell-Bloch
equations. The counter-rotating terms in the spontaneous emission damping are
included such that the equations of motion are slightly different from the
conventional Bloch equations. The counter-rotating terms can considerably
suppress the broadening of the pulse envelope and the decrease of the group
velocity rooted from dispersion. Furthermore, for incident single-cycle pulses
with envelope area 4, the time-delay of the generated soliton pulse from
the main pulse depends crucially on the carrier-envelope phase of the incident
pulse. This can be utilized to determine the carrier-envelope phase of the
single-cycle laser pulse.Comment: 6 pages, 5 figure
Partial entropy in finite-temperature phase transitions
It is shown that the von Neumann entropy, a measure of quantum entanglement,
does have its classical counterpart in thermodynamic systems, which we call
partial entropy. Close to the critical temperature the partial entropy shows
perfect finite-size scaling behavior even for quite small system sizes. This
provides a powerful tool to quantify finite-temperature phase transitions as
demonstrated on the classical Ising model on a square lattice and the
ferromagnetic Heisenberg model on a cubic lattice.Comment: 4 pages, 6 figures, Revised versio
The CO A-X System for Constraining Cosmological Drift of the Proton-Electron Mass Ratio
The band system of carbon monoxide,
which has been detected in six highly redshifted galaxies (), is
identified as a novel probe method to search for possible variations of the
proton-electron mass ratio () on cosmological time scales. Laboratory
wavelengths of the spectral lines of the A-X (,0) bands for have
been determined at an accuracy of
through VUV Fourier-transform absorption spectroscopy, providing a
comprehensive and accurate zero-redshift data set. For the (0,0) and (1,0)
bands, two-photon Doppler-free laser spectroscopy has been applied at the accuracy level, verifying the absorption data. Sensitivity
coefficients for a varying have been calculated for the CO A-X
bands, so that an operational method results to search for -variation.Comment: 7 pages (main article), 3 figures, includes supplementary materia
Compression of Atomic Phase Space Using an Asymmetric One-Way Barrier
We show how to construct asymmetric optical barriers for atoms. These
barriers can be used to compress phase space of a sample by creating a confined
region in space where atoms can accumulate with heating at the single photon
recoil level. We illustrate our method with a simple two-level model and then
show how it can be applied to more realistic multi-level atoms
On the transport and thermodynamic properties of quasi-two-dimensional purple bronzes AMoO (A=Na, K)
We report a comparative study of the specific heat, electrical resistivity
and thermal conductivity of the quasi-two-dimensional purple bronzes
NaMoO and KMoO, with special emphasis on
the behavior near their respective charge-density-wave transition temperatures
. The contrasting behavior of both the transport and the thermodynamic
properties near is argued to arise predominantly from the different
levels of intrinsic disorder in the two systems. A significant proportion of
the enhancement of the thermal conductivity above in
NaMoO, and to a lesser extent in KMoO, is
attributed to the emergence of phason excitations.Comment: 8 pages, 6 figures, To appear in Physical Review
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