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Temperature-dependent photoemission spectral weight transfer and chemical potential shift in PrCaMnO : Implications for charge density modulation
We have studied the temperature dependence of the photoemission spectra of
PrCaMnO (PCMO) with , 0.3 and 0.5. For and 0.5,
we observed a gap in the low-temperature CE-type charge-ordered (CO) phase and
a pseudogap with a finite intensity at the Fermi level () in the
high-temperature paramagnetic insulating (PI) phase. Within the CO phase, the
spectral intensity near gradually increased with temperature. These
observations are consistent with the results of Monte Carlo simulations on a
model including charge ordering and ferromagnetic fluctuations [H. Aliaga {\it
et al.} Phys. Rev. B {\bf 68}, 104405 (2003)]. For , on the other hand,
little temperature dependence was observed within the low-temperature
ferromagnetic insulating (FI) phase and the intensity at remained low in
the high-temperature PI phase. We attribute the difference in the temperature
dependence near between the CO and FI phases to the different correlation
lengths of orbital order between both phases. Furthermore, we observed a
chemical potential shift with temperature due to the opening of the gap in the
FI and CO phases. The doping dependent chemical potential shift was recovered
at low temperatures, corresponding to the disappearance of the doping dependent
change of the modulation wave vector. Spectral weight transfer with hole
concentration was clearly observed at high temperatures but was suppressed at
low temperatures. We attribute this observation to the fixed periodicity with
hole doping in PCMO at low temperatures.Comment: 5pages, 7figure
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The Long Term Temperature Variation in the Lunar Subsurface
Introduction: Lunar surface heat flow values were measured directly during the Apollo missions. These experiments were carried out on Apollo 15 and 17 for about six years between July 7, 1971 and September 30, 1977. The heat flow values derived from these two measurement sites were 21 mW/m2 and 14 mW/m2 respectively [1]. Langseth et al. concluded the repre-sentative global lunar heat flow to be around 18 mW/m2 based on approximately the first 3 years of data until the end of the 1974 (see Figure 1).
Recently, Saito et al. (2006) succeeded in archiving the heat flow data from March 1 1976 until September 30th 1977 [2]. These data are very useful for identify-ing this very long-term variation because we could extend the period of data almost by a factor of two (from 3 years to 6 years) compared to the data ar-chived previously. Because an anomaly had occurred on April 28th, 1976 on the Apollo 15 experiment, the data of Apollo 15 could not be expanded. Therefore, the data obtained by Apollo 17 were used for long term analysis
Effect of the Vortices on the Nuclear Spin Relaxation Rate in the Unconventional Pairing States of the Organic Superconductor (TMTSF)PF
This Letter theoretically discusses quasiparticle states and nuclear spin
relaxation rates in a quasi-one-dimensional superconductor
(TMTSF)PF under a magnetic field applied parallel to the conduction
chains. We study the effects of Josephson-type vortices on by
solving the Bogoliubov de Gennes equation for -, - or -wave pairing
interactions. In the presence of line nodes in pairing functions, is
proportional to in sufficiently low temperatures because quasiparticles
induced by vortices at the Fermi energy relax spins. We also try to identify
the pairing symmetry of (TMTSF)PF.Comment: 4+ pages, 4 figure
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