1,879,561 research outputs found
Father Time. I. Does the Cosmic Microwave Background Radiation Provide a Universal Arrow of Time ?
The existence of a non-thermodynamic arrow of time was demonstrated in a
recent paper (Mod.Phys.Lett. A13, 1265 (1998)), in which a model of non-local
Quantum Electrodynamics was formulated through the principle of gauge
invariance. In this paper we show that the Cosmic Microwave Background
Radiation is capable of making every particle of the universe (except those
which are not acted upon by an electromagnetic field) follow this arrow of
time.Comment: To appear in Mod.Phys.Lett. A. This is a slightly revised version
which has been communicated to the EPS-HEP99 Conference at Tampere, Finland
(15-21 July 1999) [Abs 12_204
‘The party’s over’: critical junctures, crises and the politics of housing policy
The key argument set out in this article is that historical and comparative forms of investigation are necessary if we are to better understand the ambitions and scope of contemporary housing interventions. To demonstrate the veracity of our claim, we have set out an analysis of the UK housing polices enacted in the mid-1970s as a basis for comparison with those pursued 40 years later. The article begins with a critical summary of some of the methodological approaches adopted by researchers used to interpret housing policy. In the main section, we present our critical analysis of housing policy reforms (implemented by the Labour government between 1974 and 1979) noting both their achievements and limitations. In the concluding section, we use our interpretation of this period as a basis to judge contemporary housing policy and reflect on the methodological issues that arise from our analysis
Ground state of Li and Be using explicitly correlated functions
We compare the explicitly correlated Hylleraas and exponential basis sets in
the evaluations of ground state of Li and Be. Calculations with Hylleraas
functions are numerically stable and can be performed with the large number of
basis functions. Our results for ground state energies , of Li and Be correspondingly, are the
most accurate to date. When small basis set is considered, explicitly
correlated exponential functions are much more effective. With only 128
functions we obtained about relative accuracy, but the severe
numerical instabilities make this basis costly in the evaluation.Comment: 15 page
Single-crystal growth of underdoped Bi-2223
To investigate the origin of the enhanced Tc ({\approx} 110 K) of the
trilayer cuprate superconductor Bi2Sr2Ca2Cu3O10+{\delta} (Bi-2223), its
underdoped single crystals are a critical requirement. Here, we demonstrate the
first successful in-plane resistivity measurements of heavily underdoped
Bi-2223 (zero-resistivity temperatures {\approx} 20~35 K). Detailed crystal
growth methods, the annealing process, as well as X-ray diffraction (XRD) and
magnetic susceptibility measurement results are also reported.Comment: 4 pages, 4 figures, 27th International Symposium on
Superconductivity, ISS 2014, to appear in Physics Procedi
Quantum phase slip interference device based on superconducting nanowire
We propose a transistor-like circuit including two serially connected
segments of a narrow superconducting nanowire joint by a wider segment with a
capacitively coupled gate in between. This circuit is made of amorphous NbSi
film and embedded in a network of on-chip Cr microresistors ensuring a
sufficiently high external electromagnetic impedance. Assuming a virtual regime
of quantum phase slips (QPS)in two narrow segments of the wire, leading to
quantum interference of voltages on these segments, this circuit is dual to the
dc SQUID. Our samples demonstrated appreciable Coulomb blockade voltage (analog
of critical current of the SQUIDs) and periodic modulation of this blockade by
an electrostatic gate (analog of flux modulation in the SQUIDs). The model of
this QPS transistor is discussed.Comment: 5 pages including 3 figures; in v2 the title was updated, typos were
fixed and 4 references adde
Electron Mass Enhancement due to Anharmonic Local Phonons
In order to understand how electron effective mass is enhanced by anharmonic
local oscillation of an atom in a cage composed of other atoms, i.e., {\it
rattling}, we analyze anharmonic Holstein model by using a Green's function
method. Due to the evaluation of an electron mass enhancement factor , we
find that becomes maximum when zero-point energy is comparable with
potential height at which the amplitude of oscillation is rapidly enlarged.
Cooperation of such quantum and rattling effects is considered to be a key
issue to explain the electron mass enhancement in electron-rattling systems.Comment: 3 pages, 3 figures, to appear in J. Phys. Soc. Jpn. Suppl.
(Proceedings for International Conference on Heavy Electrons
Quadrupole Susceptibility of Gd-Based Filled Skutterudite Compounds
It is shown that quadrupole susceptibility can be detected in Gd compounds
contrary to our textbook knowledge that Gd ion induces pure spin moment
due to the Hund's rules in an coupling scheme. The ground-state multiplet
of Gd is always characterized by =7/2, where denotes total
angular momentum, but in a - coupling scheme, one electron in =7/2
octet carries quadrupole moment, while other six electrons fully occupy =5/2
sextet, where denotes one-electron total angular momentum. For realistic
values of Coulomb interaction and spin-orbit coupling, the ground-state
wavefunction is found to contain significant amount of the - coupling
component. From the evaluation of quadrupole susceptibility in a simple
mean-field approximation, we point out a possibility to detect the softening of
elastic constant in Gd-based filled skutterudites.Comment: 8 pages, 4 figure
Majorana Fermion Induced Resonant Andreev Reflection
We describe experimental signatures of Majorana fermion edge states, which
form at the interface between a superconductor and the surface of a topological
insulator. If a lead couples to the Majorana fermions through electron
tunneling, the Majorana fermions induce \textit{resonant} Andreev reflections
from the lead to the grounded superconductor. The linear tunneling conductance
is () if there is an even (odd) number of vortices in the
superconductor. Similar resonance occurs for tunneling into the zero mode in
the vortex core. We also study the current and noise of a two-lead device.Comment: 4 pages, 3 figures. Discussion on STM tunneling into the Majorana
zero mode in the vortex core is adde
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