7,988 research outputs found
muSR study of the Cu-spin dynamics in the electron-doped high-Tc cuprate of Pr0.86LaCe0.14Cu1-y(Zn,Ni)yO4
Effects of the Zn- and Ni-substitution on the Cu-spin dynamics in the
electron-doped Pr0.86LaCe0.14Cu1-y(Zn,Ni)yO4+a-d with y = 0, 0.01, 0.02, 0.05
and different values of the reduced oxygen content d have been studied using
zero-field muon-spin-relaxation (muSR) measurements at temperatures down to 2
K. For the as-grown sample (d = 0, y = 0) and the sample with a very small d
value (d < 0.01, y = 0), a muon-spin precession due to long-range
antiferromagnetic order has been observed. On the other hand, no precession has
been observed for moderately oxygen-reduced samples (0.01 < d < 0.09). It has
been found that for all the samples of 0.01 < d < 0.09 the asymmetry A(t) (muSR
time spectrum) in the long-time region increases with decreasing temperature at
low temperatures, suggesting possible slowing-down of the Cu-spin fluctuations.
On the other hand, no significant difference between Zn- and Ni-substitution
effects on the slowing down of the Cu-spin fluctuations has been observed.Comment: 4 pages, 2 figures, Proceeding of 10th muSR conference 2005, to be
published in Physica
New distributed offline processing scheme at Belle
The offline processing of the data collected by the Belle detector has been
recently upgraded to cope with the excellent performance of the KEKB
accelerator. The 127/fb of data (120 TB on tape) collected between autumn 2003
and summer 2004 has been processed in 2 months, thanks to the high speed and
stability of the new, distributed processing scheme. We present here this new
processing scheme and its performance.Comment: 4 pages, 8 figures, uses CHEP2004.cl
Modulated Vortex Lattice in High Fields and Gap Nodes
The mean field vortex phase diagram of a quasi two dimensional superconductor
with a nodal d-wave pairing and with strong Pauli spin depairing is examined in
the parallel field case in order to examine an effect of gap nodes (or minima)
on the stability of a FFLO-like vortex lattice. We find through a heuristic
argument and a model calculation with a four-fold anisotropic Fermi velocity
that the FFLO-like state is relatively suppressed as the field approaches a
nodal direction. When taking account of a couple of experimental results
altogether, the present result strongly suggests that a node or gap minimum of
the pairing function of CeCoIn is located along the [100]-direction.Comment: 5 pages, 2 figures, References were added. To appear in Phys. Rev.
Absence of the impurity-induced magnetic order in the electron-doped high-T_c_ cuprates Pr_0.86_LaCe_0.14_Cu_1-y_(Zn, Ni)_y_O_4_
Zero-field muon-spin-relaxation measurements have been carried out in order
to investigate the Zn- and Ni-substitution effects on the Cu-spin dynamics in
the electron-doped Pr_0.86_LaCe_0.14_Cu_1-y_(Zn, Ni)_y_O_4+\alpa-\delta_ with y
= 0, 0.01, 0.02, 0.05 and different values of the reduced oxygen content
\delta(\delta \le 0.09). For the samples with y = 0 and very small \delta
values of \delta < 0.01, a muon-spin precession due to the formation of a
long-range antiferromagnetic order has been observed at low temperatures below
\~ 5 K. For the moderately oxygen-reduced samples of 0.01 \le \delta \le 0.09,
on the contrary, no muon-spin precession has been observed and the temperature
dependence of the spectra is similar to one another regardless of the y value.
That is, no impurity-induced slowing down of the Cu-spin fluctuations has been
detected, which is very different from the results of the hole-doped high-T_c_
cuprates. The reason is discussed.Comment: 13 pages, 2 figures, Proceedings of ISS2004 (to be published in
Physica C
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