10,042 research outputs found
Symmetry and Z_2-Orbifolding Approach in Five-dimensional Lattice Gauge Theory
In a lattice gauge-Higgs unification scenario using a Z_2-orbifolded
extra-dimension, we find a new global symmetry in a case of SU(2) bulk gauge
symmetry. It is a global symmetry on sites in a fixed point with respect to
Z_2-orbifolding, independent of the bulk gauge symmetry. It is shown that the
vacuum expectation value of a Z_2-projected Polyakov loop is a good order
parameter of the new symmetry. The effective theory on lattice is also
discussed.Comment: 13 pages, 3 figures; refined the explanation
Scattering and Pairing in Cuprate Superconductors
The origin of the exceptionally strong superconductivity of cuprates remains
a subject of debate after more than two decades of investigation. Here we
follow a new lead: The onset temperature for superconductivity scales with the
strength of the anomalous normal-state scattering that makes the resistivity
linear in temperature. The same correlation between linear resistivity and Tc
is found in organic superconductors, for which pairing is known to come from
fluctuations of a nearby antiferromagnetic phase, and in pnictide
superconductors, for which an antiferromagnetic scenario is also likely. In the
cuprates, the question is whether the pseudogap phase plays the corresponding
role, with its fluctuations responsible for pairing and scattering. We review
recent studies that shed light on this phase - its boundary, its quantum
critical point, and its broken symmetries. The emerging picture is that of a
phase with spin-density-wave order and fluctuations, in broad analogy with
organic, pnictide, and heavy-fermion superconductors.Comment: To appear in Volume 1 of the Annual Review of Condensed Matter
Physic
Induced Magnetic Ordering by Proton Irradiation in Graphite
We provide evidence that proton irradiation of energy 2.25 MeV on
highly-oriented pyrolytic graphite samples triggers ferro- or ferrimagnetism.
Measurements performed with a superconducting quantum interferometer device
(SQUID) and magnetic force microscopy (MFM) reveal that the magnetic ordering
is stable at room temperature.Comment: 3 Figure
Investigation of Visual Management Cases in Construction by an Analytical Framework from Manufacturing
Along with the progress of globalization, speed and efficiency have become more critical for any industry than ever before. In this sense, the concept and methods of lean management, promoting these performances, have been deployed from manufacturing, its origin industry, to other industries. This paper deals with this management style in the construction industry, called lean construction. In particular, visual management (VM) as one effective tool in this scheme is focused on. A number of VM cases, 306 in total, was collected from both construction and manufacturing sites and investigated by the so-called 5W1H analytical framework developed in the manufacturing industry. Obtained results suggest that the VM cases in construction have common attributes such as purpose and location, target to attain, users’ attributes, timing to use and elemental technologies for case development. A comparison analysis of the VM cases from construction and those from manufacturing was also carried out, for a mutual transfer of this technology between these industries
Long-Range Excitons in Optical Absorption Spectra of Electroluminescent Polymer Poly(para-phenylenevinylene)
The component of photoexcited states with large spatial extent is
investigated for poly(para-phenylenevinylene) using the intermediate exciton
theory. We find a peak due to long-range excitons at the higher-energy side of
the lowest main feature of optical spectra. The fact that the onset of
long-range excitons is located near the energy gap is related to the mechanisms
of large photocurrents measured in such energy regions. We show that a large
value of the hopping integral is realistic for characterizing optical
excitations.Comment: To be published in J. Phys. Soc. Jpn. (Letters
Vacuum Structure of the Ichimatsu-Decomposed Lattice Models
We proposed an `Ichimatsu'-decomposed lattice gauge theory with fermionic
symmetries. The vacuum structures of the gauge sector with two coupling
constants () are investigated for 3-dimensional Z and
4-dimensional SU(2) cases using mean-field approximation and numerical
simulation. We found two phases on the () phase diagram for
3-dim. Z case, while the diagram is a single phase for the latter.Comment: 3 pages, 6 figures, Lattice2002(higgssusy
Thermoelectric figure of merit of tau-type conductors of several donors
Dimensionless thermoelectric figure of merit is investigated for
two-dimensional organic conductors ,
-(EDT-S,S-DMEDT-TTF)_2(AuI_2)_{1+y}\tau (), respectively. The
values were estimated by measuring electrical resistivity, thermopower and
thermal conductivity simultaneously. The largest is 2.7 10
at 155 K for , 1.5 10
at 180 K for and 5.4
10 at 78 K for , respectively.
Substitution of the donor molecules fixing the counter anion revealed
EDT-S,S-DMEDT-TTF is the best of the three donors to obtain larger .Comment: proceedings of ISCOM 2009 (to be published in Physica B
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