29,595 research outputs found
Finite temperature superfluid density in very underdoped cuprates
The combination of a large superconducting gap, low transition temperature,
and quasi two-dimensionality in strongly underdoped high temperature
superconductors severely constrains the behavior of the ab-plane superfluid
density \rho with temperature T. In particular, we argue that the contribution
of nodal quasiparticles to \rho(T) is essential to account both for the
amplitude of, and the recently observed deviations from, the Uemura scaling. A
relation between T_c and \rho(0) which combines the effects of quasiparticle
excitations at low temperatures and of vortex fluctuations near the critical
temperature is proposed and discussed in light of recent experiments.Comment: 5 RevTex pages, 4 figures (one new); more discussion and comparison
with experiment; version to appear in Phys. Rev.
Magnetic field induced 3D to 1D crossover in type II superconductors
We review and analyze magnetization and specific heat investigations on
type-II superconductors which uncover remarkable evidence for the magnetic
field induced fnite size effect and the associated 3D to 1D crossover which
enhances thermal fluctuations.Comment: 26 pages, 19 figure
Evaluation of the impact on audiences of Inside Out of Mind, research-based theatre for dementia carers
Background
Inside Out of Mind is an ethno-drama about dementia carers in hospital, intended to raise awareness of this role, and about dementia care in general. Following a successful premiere in 2013, it was taken on a live tour funded by the Big Lottery through Arts Council England to six cities. This paper explores the impact on audiences consisting largely of professional carers.
Methods
Mixed methods were applied; semi-structured self-completion questionnaires for post-show feedback, and one month later telephone interviews to a stratified sample of respondents. Framework analysis was used to explore the data, paying particular attention to critical comments.
Results
Of the 5,426 people who attended, 19% completed post-show questionnaires. Sixty-four were subsequently interviewed in depth. Both lay and professional audience members expressed heightened awareness of the needs of people with dementia. They expressed greater appreciation of the care process and the challenges faced by the people employed to care for people with dementia in hospitals and other long-term settings.
Conclusions
As research-based theatre this production of Inside Out of Mind afforded an effective medium for knowledge transfer. It engaged audiences with the key issues - including dignity, identity and loss - and enabled them to relate these to their own lives, while encouraging appropriate practical responses
g-factor of a tightly bound electron
We study the hyperfine splitting of an electron in hydrogen-like . It is found that the hfs energy splitting can be explained well by
considering the g-factor reduction due to the binding effect of a bound
electron. We determine for the first time the experimental value of the
magnetic moment of a tightly bound electron.Comment: 6 pages, Latex, Phys. Rev. A in pres
Isotope effects in underdoped cuprate superconductors: a quantum phenomenon
We show that the unusual doping dependence of the isotope effects on
transition temperature and zero temperature in - plane penetration depth
naturally follows from the doping driven 3D-2D crossover, the 2D quantum
superconductor to insulator transition (QSI) in the underdoped limit and the
change of the relative doping concentration upon isotope substitution. Close to
the QSI transition both, the isotope coefficient of transition temperature and
penetration depth approach the coefficient of the relative dopant
concentration, and its divergence sets the scale. These predictions are fully
consistent with the experimental data and imply that close to the underdoped
limit the unusual isotope effect on transition temperature and penetration
depth uncovers critical phenomena associated with the quantum superconductor to
insulator transition in two dimensions.Comment: 6 pages, 3 figure
Theory of non-equilibrium electronic Mach-Zehnder interferometer
We develop a theoretical description of interaction-induced phenomena in an
electronic Mach-Zehnder interferometer formed by integer quantum Hall edge
states (with \nu =1 and 2 channels) out of equilibrium. Using the
non-equilibrium functional bosonization framework, we derive an effective
action which contains all the physics of the problem. We apply the theory to
the model of a short-range interaction and to a more realistic case of
long-range Coulomb interaction. The theory takes into account
interaction-induced effects of dispersion of plasmons, charging, and
decoherence. In the case of long-range interaction we find a good agreement
between our theoretical results for the visibility of Aharonov-Bohm
oscillations and experimental data.Comment: 19 pages, 10 figure
Low-Spin Spectroscopy of 50Mn
The data on low spin states in the odd-odd nucleus 50Mn investigated with the
50Cr(p,ngamma)50Mn fusion evaporation reaction at the FN-TANDEM accelerator in
Cologne are reported. Shell model and collective rotational model
interpretations of the data are given.Comment: 7 pages, 2 figures, to be published in the proceedings of the
"Bologna 2000 - Structure of the Nucleus at the Dawn of the Century"
Conference, (Bologna, Italy, May 29 - June 3, 2000
Multi-layer atom chips for versatile atom micro manipulation
We employ a combination of optical UV- and electron-beam-lithography to
create an atom chip combining sub-micron wire structures with larger
conventional wires on a single substrate. The new multi-layer fabrication
enables crossed wire configurations, greatly enhancing the flexibility in
designing potentials for ultra cold quantum gases and Bose-Einstein
condensates. Large current densities of >6 x 10^7 A/cm^2 and high voltages of
up to 65 V across 0.3 micron gaps are supported by even the smallest wire
structures. We experimentally demonstrate the flexibility of the next
generation atom chip by producing Bose-Einstein condensates in magnetic traps
created by a combination of wires involving all different fabrication methods
and structure sizes.Comment: 4 pages, 5 figure
Gravitational Lensing by Power-Law Mass Distributions: A Fast and Exact Series Approach
We present an analytical formulation of gravitational lensing using familiar
triaxial power-law mass distributions, where the 3-dimensional mass density is
given by . The deflection angle and magnification factor are
obtained analytically as Fourier series. We give the exact expressions for the
deflection angle and magnification factor. The formulae for the deflection
angle and magnification factor given in this paper will be useful for numerical
studies of observed lens systems. An application of our results to the Einstein
Cross can be found in Chae, Turnshek, & Khersonsky (1998). Our series approach
can be viewed as a user-friendly and efficient method to calculate lensing
properties that is better than the more conventional approaches, e.g.,
numerical integrations, multipole expansions.Comment: 24 pages, 3 Postscript figures, ApJ in press (October 10th
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