22,846 research outputs found
Corner contributions to holographic entanglement entropy in non-conformal backgrounds
We study corner contributions to holographic entanglement entropy in
non-conformal backgrounds: a kink for D2-branes as well as a cone and two
different types of crease for D4-branes. Unlike 2+1-dimensional CFTs, the
corner contribution to the holographic entanglement entropy of D2-branes
exhibits a power law behaviour rather than a logarithmic term. However, the
logarithmic term emerges in the holographic entanglement entropy of D4-branes.
We identify the logarithmic term for a cone in D4-brane background as the
universal contribution under appropriate limits and compare it with other
physical quantities.Comment: 25 pages, 1 figure, discussions in section 5.2 improved, typos
corrected and references adde
Migrants from the People's Republic of China to Australia : a study of family practices
Since the late 1970s, dramatic social changes in the People's Republic of China have led to a sudden emigration of Chinese from China to Australia. Given the obvious social and cultural differences between the two societies, what has been the impact of this cross-country migration upon the migrants' family lives in their new country of residence? How do they cope with the changing social context? Are there patterns within their family practices which are distinctive from those of the mainstream society? This study has examined family practices through in-depth interviews of 40 Chinese migrants who immigrated to Australia in the past two decades. The study is intended to be broadly contextualized and historical in scope. Hence, overviews of family traditions, culture and contemporary changes in both the home and host countries are elaborated. An analysis of the informants' motivations for migration and perceptions of the host society are also examined in significant detail, as the respondents' motivations and perceptions have implications for the ways they have chosen to reorganize their lives in a new country. Family life including marriage, attitudes towards sexuality, child rearing and the division of labour at home were probed among this sample within broad frameworks utilizing scholarly perspectives of immigration, ethnoculture and gender relations
Detecting the orbital character of the spin fluctuation in the Iron-based superconductors with the resonant inelastic X-ray scattering spectroscopy
The orbital distribution of the spin fluctuation in the iron-based
superconductors(IBSs) is the key information needed to understand the
magnetism, superconductivity and electronic nematicity in these multi-orbital
systems. In this work, we propose that the resonant inelastic X-ray
scattering(RIXS) technique can be used to probe selectively the spin
fluctuation on different Fe orbitals. In particular, the spin fluctuation
on the three orbitals, namely, the , and the
orbital, can be selectively probed in the
scattering geometry by aligning the direction of the outgoing photon in the
, and direction. Such orbital-resolved information on the spin
fluctuation is invaluable for the study of the orbital-selective physics in the
IBSs and can greatly advance our understanding on the relation between orbital
ordering and spin nematicity in the IBSs and the orbital-selective pairing
mechanism in these multi-orbital systems.Comment: 6 pages with new and more informative figures, the explicit form of
the RIXS matrix element is provided, and the discussion part has been
rewritte
Vanishing pseudogap around in an electron-doped high- superconductor: a simple picture
Recent ARPES measurement on electron-doped cuprate
finds
that the pseudogap along the boundary of the antiferromagnetic Brillouin
zone(AFBZ) exhibits dramatic momentum dependence. In particular, the pseudogap
vanishes in a finite region around the anti-nodal point, in which a single
broadened peak emerges at the un-renormalized quasiparticle energy. Such an
observation is argued to be inconsistent with the antiferromagnetic(AFM)
band-folding picture, which predicts a constant pseudogap along the AFBZ
boundary. On the other hand, it is claimed that the experimental results are
consistent with the prediction of the cluster dynamical mean field
theory(CDMFT) simulation on the Hubbard model, in which the pseudogap is
interpreted as a s-wave splitting between the Hubbard bands and the in-gap
states. Here we show that the observed momentum dependence of the pseudogap is
indeed consistent with AFM band-folding picture, provided that we assume the
existence of a strongly momentum dependent quasiparticle scattering rate. More
specifically, we show that the quasiparticle scattering rate acts to reduce the
spectral gap induced by AFM band-folding effect. The new quasiparticle poles
corresponding to the AF-split bands can even be totally eliminated when the
scattering rate exceeds the bare band folding gap, leaving the system with a
single pole at the un-renormalized quasiparticle energy. We predict that the
pseudogap should close in a square root fashion as we move toward
along the AFBZ boundary. Our results illustrates again that the quasiparticle
scattering rate can play a much more profound role than simply broadening the
quasiparticle peak in the quasiparticle dynamics of strongly correlated
electron systems.Comment: 5 pages, 2 figures, new references adde
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