19,034 research outputs found
High-Resolution Crystal Truncation Rod Scattering: Application to Ultrathin Layers and Buried Interfaces
In crystalline materials, the presence of surfaces or interfaces gives rise to crystal truncation rods (CTRs) in their Xâray diffraction patterns. While structural properties related to the bulk of a crystal are contained in the intensity and position of Bragg peaks in Xâray diffraction, CTRs carry detailed information about the atomic structure at the interface. Developments in synchrotron Xâray sources, instrumentation, and analysis procedures have made CTR measurements into extremely powerful tools to study atomic reconstructions and relaxations occurring in a wide variety of interfacial systems, with relevance to chemical and electronic functionalities. In this review, an overview of the use of CTRs in the study of atomic structure at interfaces is provided. The basic theory, measurement, and analysis of CTRs are covered and applications from the literature are highlighted. Illustrative examples include studies of complex oxide thin films and multilayers
More on N=1 Matrix Model Curve for Arbitrary N
Using both the matrix model prescription and the strong-coupling approach, we
describe the intersections of n=0 and n=1 non-degenerated branches for quartic
(polynomial of adjoint matter) tree-level superpotential in N=1 supersymmetric
SO(N)/USp(2N) gauge theories with massless flavors. We also apply the method to
the degenerated branch. The general matrix model curve on the two cases we
obtain is valid for arbitrary N and extends the previous work from
strong-coupling approach. For SO(N) gauge theory with equal massive flavors, we
also obtain the matrix model curve on the degenerated branch for arbitrary N.
Finally we discuss on the intersections of n=0 and n=1 non-degenerated branches
for equal massive flavors.Comment: 36pp; to appear in JHE
The Impact of Unemployment on Individual Well-Being in the EU. CEPS ENEPRI Working Papers No. 29, 1 July 2004
Among the working-age population, one of the most damaging individual experiences is unemployment. Many previous studies have confirmed the devastating effects of unemployment on individual well-being, both pecuniary and non-pecuniary. Using the data from the European Community Household Panel survey, this paper examines the factors that affect unemployed workersâ well-being with respect to their situations in their main vocational activity, income, housing, leisure time and health in Europe. The research finds that unemployment substantially reduces an individualâs satisfaction levels with his or her main vocational activity and finance, while it greatly increases his or her satisfaction levels with leisure time. With respect to health, it has a small negative effect. Unemployment duration also has a small, negative impact on individual well-being, suggesting that unemployment has a lasting and aggravating effect throughout the spells of unemployment, contradicting the theory of adaptation
Geometrically Induced Phase Transitions at Large N
Utilizing the large N dual description of a metastable system of branes and
anti-branes wrapping rigid homologous S^2's in a non-compact Calabi-Yau
threefold, we study phase transitions induced by changing the positions of the
S^2's. At leading order in 1/N the effective potential for this system is
computed by the planar limit of an auxiliary matrix model. Beginning at the two
loop correction, the degenerate vacuum energy density of the discrete confining
vacua split, and a potential is generated for the axion. Changing the relative
positions of the S^2's causes discrete jumps in the energetically preferred
confining vacuum and can also obstruct direct brane/anti-brane annihilation
processes. The branes must hop to nearby S^2's before annihilating, thus
significantly increasing the lifetime of the corresponding non-supersymmetric
vacua. We also speculate that misaligned metastable glueball phases may
generate a repulsive inter-brane force which stabilizes the radial mode present
in compact Calabi-Yau threefolds.Comment: 47 pages, 7 figure
The Conflict between Bell-Zukowski Inequality and Bell-Mermin Inequality
We consider a two-particle/two-setting Bell experiment to visualize the
conflict between Bell-\.Zukowski inequality and Bell-Mermin inequality. The
experiment is reproducible by local realistic theories which are not
rotationally invariant. We found that the average value of the Bell-\.Zukowski
operator can be evaluated only by the two-particle/two-setting Bell experiment
in question. The Bell-\.Zukowski inequality reveals that the constructed local
realistic models for the experiment are not rotationally invariant. That is,
the two-particle Bell experiment in question reveals the conflict between
Bell-\.Zukowski inequality and Bell-Mermin inequality. Our analysis has found
the threshold visibility for the two-particle interference to reveal the
conflict noted above. It is found that the threshold visibility agrees with the
value to obtain a violation of the Bell-\.Zukowski inequality.Comment: To appear in Modern Physics Letters
The Large N 't Hooft Limit of Kazama-Suzuki Model
We consider N=2 Kazama-Suzuki model on CP^N=SU(N+1)/SU(N)xU(1). It is known
that the N=2 current algebra for the supersymmetric WZW model, at level k, is a
nonlinear algebra. The N=2 W_3 algebra corresponding to N=2 was recovered from
the generalized GKO coset construction previously. For N=4, we construct one of
the higher spin currents, in N=2 W_5 algebra, with spins (2, 5/2, 5/2, 3). The
self-coupling constant in the operator product expansion of this current and
itself depends on N as well as k explicitly. We also observe a new higher spin
primary current of spins (3, 7/2, 7/2, 4). From the behaviors of N=2, 4 cases,
we expect the operator product expansion of the lowest higher spin current and
itself in N=2 W_{N+1} algebra. By taking the large (N, k) limit on the various
operator product expansions in components, we reproduce, at the linear order,
the corresponding operator product expansions in N=2 classical
W_{\infty}^{cl}[\lambda] algebra which is the asymptotic symmetry of the higher
spin AdS_3 supergravity found recently.Comment: 44 pages; the two typos in the first paragraph of page 23 corrected
and to appear in JHE
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