14,361 research outputs found
Effective Lagrangian and Topological Interactions in Supersolids
We construct a low-energy effective Lagrangian describing zero-temperature
supersolids. Galilean invariance imposes strict constraints on the form of the
effective Lagrangian. We identify a topological term in the Lagrangian that
couples superfluid and crystalline modes. For small superfluid fractions this
interaction term is dominant in problems involving defects. As an illustration,
we compute the differential cross section of scatterings of low-energy
transverse elastic phonons by a superfluid vortex. The result is
model-independent.Comment: 10 pages, 1 figure; one reference adde
Does parton saturation at high density explain hadron multiplicities at LHC?
An addendum to our previous papers in Phys. Lett. B539 (2002) 46 and Phys.
Lett. B502 (2001) 51, contributed to the CERN meeting "First data from the LHC
heavy ion run", March 4, 2011Comment: 6 pages, contribution to the CERN meeting "First data from the LHC
heavy ion run", March 4, 201
Infrared Hall conductivity of NaCoO
We report infrared Hall conductivity of
NaCoO thin films determined from Faraday rotation angle
measurements. exhibits two types of hole
conduction, Drude and incoherent carriers. The coherent Drude carrier shows a
large renormalized mass and Fermi liquid-like behavior of Hall scattering rate,
. The spectral weight is suppressed and disappears at T
= 120K. The incoherent carrier response is centered at mid-IR frequency and
shifts to lower energy with increasing T. Infrared Hall constant is positive
and almost independent of temperature in sharp contrast with the dc-Hall
constant.Comment: 5 Pages, 5 Figures. Author list corrected in metadata only, paper is
unchange
Asymptotic deconfinement in high-density QCD
We discuss QCD with two light flavors at large baryon chemical potential mu.
Color superconductivity leads to partial breaking of the color SU(3) group. We
show that the infrared physics is governed by the gluodynamics of the remaining
SU(2) group with an exponentially soft confinement scale Lambda_QCD'
Delta*exp[-a*mu/(g*Delta)], where Delta<<mu is the superconducting gap, g is
the strong coupling, and a=0.81... We estimate that at moderate baryon
densities Lambda_QCD' is O(10 MeV) or smaller. The confinement radius increases
exponentially with density, leading to "asymptotic deconfinement." The velocity
of the SU(2) gluons is small due to the large dielectric constant of the
medium.Comment: 4 pages; restructured, published versio
Land use survey and mapping and water resources investigation in Korea
The author has identified the following significant results. Land use imagery is applicable to land use classification for small scale land use mapping less than 1:250,000. Land use mapping by satellite is more efficient and more cost-effective than land use mapping from conventional medium altitude aerial photographs. Six categories of level 1 land use classification are recognizable from MSS imagery. A hydrogeomorphological study of the Han River basin indicates that band 7 is useful for recognizing the soil and the weathering part of bed rock. The morphological change of the main river is accurately recognized and the drainage system in the area observed is easily classified because of the more or less simple rock type. Although the direct hydrological characteristics are not obtained from the MSS imagery, the indirect information such as the permeability of the soil and the vegetation cover, is helpful in interpreting the hydrological aspects
Universal Properties of Two-Dimensional Boson Droplets
We consider a system of N nonrelativistic bosons in two dimensions,
interacting weakly via a short-range attractive potential. We show that for N
large, but below some critical value, the properties of the N-boson bound state
are universal. In particular, the ratio of the binding energies of (N+1)- and
N-boson systems, B_{N+1}/B_N, approaches a finite limit, approximately 8.567,
at large N. We also confirm previous results that the three-body system has
exactly two bound states. We find for the ground state B_3^(0) = 16.522688(1)
B_2 and for the excited state B_3^(1) = 1.2704091(1) B_2.Comment: 4 pages, 2 figures, final versio
Critical dynamics, duality, and the exact dynamic exponent in extreme type II superconductors
The critical dynamics of superconductors is studied using renormalization
group and duality arguments. We show that in extreme type II superconductors
the dynamic critical exponent is given exactly by . This result does not
rely on the widely used models of critical dynamics. Instead, it is shown that
follows from the duality between the extreme type II superconductor and
a model with a critically fluctuating gauge field. Our result is in agreement
with Monte Carlo simulations.Comment: 7 pages, no figures; version accepted for publication in PR
Valence bond solid order near impurities in two-dimensional quantum antiferromagnets
Recent scanning tunnelling microscopy (STM) experiments on underdoped
cuprates have displayed modulations in the local electronic density of states
which are centered on a Cu-O-Cu bond (Kohsaka et. al., cond-mat/0703309). As a
paradigm of the pinning of such bond-centered ordering in strongly correlated
systems, we present the theory of valence bond solid (VBS) correlations near a
single impurity in a square lattice antiferromagnet. The antiferromagnet is
assumed to be in the vicinity of a quantum transition from a magnetically
ordered Neel state to a spin-gap state with long-range VBS order. We identify
two distinct classes of impurities: i) local modulation in the exchange
constants, and ii) a missing or additional spin, for which the impurity
perturbation is represented by an uncompensated Berry phase. The `boundary'
critical theory for these classes is developed: in the second class we find a
`VBS pinwheel' around the impurity, accompanied by a suppression in the VBS
susceptibility. Implications for numerical studies of quantum antiferromagnets
and for STM experiments on the cuprates are noted.Comment: 41 pages, 6 figures; (v2) Minor changes in terminology, added
reference
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