12,995 research outputs found
Pressure, Resistance, and Current Activation of Anisotropic Compressible Hall States
Thermodynamic and electric properties of anisotropic compressible Hall states
at higher Landau levels are studied using a mean field theory on the von
Neumann lattice basis. It is shown that resistances agree with the recent
experiments of anisotropic compressible states and the states have negative
pressure. As implications, the collapse phenomena of the integer quantum Hall
effect are discussed.Comment: 4 pages, 5 figures, to be published in Physica
ASCA Observation of the Lyman-limit Quasar PKS2145+067
X-ray observation of a famous Lyman-limit quasar PKS2145+067at z_em= 0.990
was carried with ASCA. The source showed a 2-10 keV flux of 1.3 E-11 erg cm^-2
sec^-1 (L_X = 2.5 E46 erg sec^-1 for H_0=50 km s^-1 Mpc^-1) described by a
power-law spectrum with a photon index Gamma=1.63 +/- 0.04 . In the ASCA energy
band, no excess absorption was detected implying the absorption column density
at z_ ab=0.791 was less than 1.6 E21 cm^-2 if absorbing medium had a metal
abundance of 0.5 solar. Comparison with previous Einstein and ROSAT
observations shows that PKS2145+067 has increased its luminosity by a factor of
2--3 between 1991 and 1998.Comment: 15 pages, 3figures, Latex(PASJadd,sty, PASJ95.sty) accepted in PAS
Visibility and aerosol measurement by diode-laser random-modulation CW lidar
Examples of diode laser (DL) random-modulation continuous wave (RM-CW) lidar measurements are reported. The ability of the measurement of the visibility, vertical aerosol profile, and the cloud ceiling height is demonstrated. Although the data shown here were all measured at night time, the daytime measurement is, of course, possible. For that purpose, accurate control of the laser frequency to the center frequency of a narrow band filter is required. Now a new system with a frequency control is under construction
Intra-Landau level polarization effect for a striped Hall gas
We calculate the polarization function including only intra-Landau level
correlation effects of striped Hall gas. Using the polarization function, the
dielectric function, the dispersion of the plasmon and the correlation energy
are computed in a random phase approximation (RPA) and generalized random phase
approximation (GRPA). The plasmon becomes anisotropic and gapless owing to the
anisotropy of the striped Hall gas and two dimensionality of the quantum Hall
system. The plasmon approximately agrees with the phonon derived before by the
single mode approximation. The (G)RPA correlation energy is compared with other
numerical calculations.Comment: 15 pages,15 figures, revtex4, published versio
matching coefficients for axial vector current and 2 operator
We present a calculation of the perturbative matching coefficients including
mixing with higher dimensional operators for the temporal component of the
heavy-light axial current, , and the operator, . For
, calculations with various RG-improved
gauge actions are peformed. Matching coefficients with NRQCD and heavy-clover
actions are also compared.Comment: LATTICE99 (Heavy Quarks), 3 pages, 2 figures, espcrc2.st
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