2,585 research outputs found
Scaling approach to glassy stationary states of spin-glasses under chaos effects
Dynamics of spin-glasses subjected to slow continuous changes of working
enviroment such as slow changes of temperature or interaction bonds are studied
based on scaling arguments and numerical simulations of continuous bond
changes. Such perturbations lead to a glassy stationary state where the age or
domain size of the system are pinned to macroscopic but finite values due to
competition between relaxation and chaos effects (rejuvenation).
Flutuation-dissipation relation is also pinned to that of a finite age. The
scenario explains the anomalously weak cooling rate dependece of spin glasses.Comment: Contribution to SPDSA 2004, Hayama, Japa
Absolute absorption cross sections of ozone at 300 K, 228 K and 195 K in the wavelength region 185-240 nm
An account is given of progress of work on absorption cross section measurements of ozone at 300 K, 228 K and 195 K in the wavelength region 185-240 nm. In this wavelength region, the penetration of solar radiation into the Earth's atmosphere is controlled by O2 and O3. The transmitted radiation is available to dissociate trace species such as halocarbons and nitrous oxide. We have recently measured absolute absorption cross sections of O3 in the wavelength region 240-350 nm (Freeman et al., 1985; Yoshino et al., 1988). We apply these proven techniques to the determination of the absorption cross section of O3 at 300 K, 228 K and 195 K throughout the wavelength region 185-240 nm. A paper titled 'Absolute Absorption Cross Section Measurements of Ozone in the Wavelength Region 185-254 nm and the Temperature Dependence' has been submitted for publication in the Journal of Geophysical Research
Symmetrical Temperature-Chaos Effect with Positive and Negative Temperature Shifts in a Spin Glass
The aging in a Heisenberg-like spin glass Ag(11 at% Mn) is investigated by
measurements of the zero field cooled magnetic relaxation at a constant
temperature after small temperature shifts . A
crossover from fully accumulative to non-accumulative aging is observed, and by
converting time scales to length scales using the logarithmic growth law of the
droplet model, we find a quantitative evidence that positive and negative
temperature shifts cause an equivalent restart of aging (rejuvenation) in terms
of dynamical length scales. This result supports the existence of a unique
overlap length between a pair of equilibrium states in the spin glass system.Comment: 4 page
Numerical study of the ordering of the +-J XY spin-glass ladder
The properties of the domain-wall energy and of the correlation length are
studied numerically for the one-dimensional +-J XY spin glass on the two-leg
ladder lattice, focusing on both the spin and the chirality degrees of freedom.
Analytic results obtained by Ney-Niftle et al for the same model were confirmed
for asymptotically large lattices, while the approach to the asymptotic limit
is slow and sometimes even non-monotonic. Attention is called to the occurrence
of the SO(2)-Z_2 decoupling and its masking in spin correlations, the latter
reflecting the inequality between the SO(2) and Z_2 exponents. Discussion is
given concerning the behaviors of the higher-dimensional models.Comment: 14 pages, 10 figure
PICOSECOND TIME-RESOLVED STUDY OF INTERMEDIATE SPECIES PRECEDING FREE CHARGE CARRIER FORMATION
In situ real-time analysis of alloy film composition and segregation dynamics with parallel detection reflection electron energy loss spectroscopy
Real-time measurements of GexSi1 – x/Si(001) composition and segregation dynamics in Sn/Si(001) in molecular beam epitaxy are demonstrated using parallel detection reflection electron energy loss spectroscopy. Parallel detection enables quantitative acquisition of low-loss spectra in a time of < 500 µs and surface composition determination in GexSi1 – x/Si(001) via Ge L2,3 core loss analysis to a precision of approximately 2% in time of order 1 s. Segregation and trapping kinetics of monolayer thickness Sn films during Si epitaxy on Sn-covered Si(100) has also been studied using the Sn M4.5 core loss
Interference Commensurate Oscillations in Q1D Conductors
We suggest an analytical theory to describe angular magnetic oscillations
recently discovered in quasi-one-dimensional conductor (TMTSF)2PF6 [see Phys.
Rev. B, 57, 7423 (1998)] and define the positions of the oscillation minima.
The origin of these oscillations is related to interference effects resulting
from an interplay of quasi-periodic and periodic ("commensurate") electron
trajectories in an inclined magnetic field. We reproduce via calculations
existing experimental data and predict some novel effects.Comment: 10 pages, 2 figure
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