2,176 research outputs found
Effect of Disorder in the Frustrated Ising FCC Antiferromagnet: Phase Diagram and Stretched Exponential Relaxation
We study the phase transition in a face-centered-cubic antiferromagnet with
Ising spins as a function of the concentration of ferromagnetic bonds
randomly introduced into the system. Such a model describes the spin-glass
phase at strong bond disorder. Using the standard Monte Carlo simulation and
the powerful Wang-Landau flat-histogram method, we carry out in this work
intensive simulations over the whole range of . We show that the first-order
transition disappears with a tiny amount of ferromagnetic bonds, namely , in agreement with theories and simulations on other 3D models. The
antiferromagnetic long-range order is also destroyed with a very small
(). With increasing , the system changes into a spin glass and
then to a ferromagnetic phase when . The phase diagram in the space
() shows an asymmetry, unlike the case of the Ising spin glass
on the simple cubic lattice. We calculate the relaxation time around the
spin-glass transition temperature and we show that the spin autocorrelation
follows a stretched exponential relaxation law where the factor is equal to
at the transition as suggested by the percolation-based theory.
This value is in agreement with experiments performed on various spin glasses
and with Monte Carlo simulations on different SG models
Spatial correlations in chaotic nanoscale systems with spin-orbit coupling
We investigate the statistical properties of wave functions in chaotic
nanostructures with spin-orbit coupling (SOC), focussing in particular on
spatial correlations of eigenfunctions. Numerical results from a microscopic
model are compared with results from random matrix theory in the crossover from
the gaussian orthogonal to the gaussian symplectic ensembles (with increasing
SOC); one- and two-point distribution functions were computed to understand the
properties of eigenfunctions in this crossover. It is found that correlations
of wave function amplitudes are suppressed with SOC; nevertheless,
eigenfunction correlations play a more important role in the two-point
distribution function(s), compared to the case with vanishing SOC. Experimental
consequences of our results are discussed.Comment: Submitted to PR
Tunneling into Nonequilibrium Luttinger Liquid with Impurity
We evaluate tunneling rates into/from a voltage biased quantum wire
containing weak backscattering defect. Interacting electrons in such a wire
form a true nonequilibrium state of the Luttinger liquid (LL). This state is
created due to inelastic electron backscattering leading to the emission of
nonequilibrium plasmons with typical frequency . The
tunneling rates are split into two edges. The tunneling exponent at the Fermi
edge is positive and equals that of the equilibrium LL, while the exponent at
the side edge is negative if Coulomb interaction is not too strong.Comment: 4+ pages, 5 figure
Analisa Pengaruh Komunikasi Internal, Intrinsic Rewards Dan Recognition Terhadap Employee Engagement Di Surabaya Suite Hotel
Penelitian ini dilakukan untuk menganalisa pengaruh komunikasi internal, intrinsic rewards, dan recognition terhadap employee engagementdi SurabayaSuiteHotel. Employee engagement penting untuk meningkatkan kinerja karyawan demi keberhasilan organisasi. Komunikasi internal adalah proses pertukaran informasi dalam internal organisasi. Intrinsic rewards adalah kepuasan pribadi dari pekerjaan itu sendiri. Dan recognition adalah pengakuan yang diberikan atas kinerja karyawan. Teknik analisa yang digunakan adalah kuantitatif kausal. Hasil analisa regresi menunjukkan bahwa komunikasi internal, intrinsic rewards dan recognition berpengaruh simultan dan signifikan terhadap employee engagement. Komunikasi internal, intrinsic rewards dan recognition secara parsial dan signifikan berpengaruh terhadap employee engagement. Sementara itu, intrinsic rewards dan recognition memiliki pengaruh dominan terhadap employee engagement
Free base and protonated form fluorescence of the mixed 5,10,15,20-arylporphyrins
Fluorescence spectra for a series of mixed phenyl-mesityl 5,10,15,20-tetraarylporphyrins – with Mes4, Mes3Ph, Mes2Ph2- trans, Mes2Ph2- cis, MesPh
3 and Ph4 type architecture (Mes – mesityl, Ph – phenyl) – in their free base, mono- and diprotonated form are reported. Substitution of a single mesophenyl group with a sterically more demanding mesityl group is found to be sufficient to provide stabi-lization of the monoprotonated porphyrin species. A decrease in the number of mesityl substituents in the macrocycle leads to a decrease in the fluore scence quantum yield for protonated forms. The pro-gressive replacement of ortho,ortho’-substituted mesityl groups with unhindered phenyls results in the additive pattern of spectral changes for the free base porphyrins, whereas for both protonated species a specific jump at the trans to cis transition is observed, along with a gradual additive pattern before and
afterwards. This feature is interpreted as a signature of the transition between the hindered-like and un-hindered-like conformations of the tetrapyrrolic m acrocycles in the protonated forms. These two mo-lecular conformations provide a different interaction of the two one-electron (a1u,eg) and (a2u,eg) configurations, which leads to changes of their contributions into electronic transitions
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