57,956 research outputs found

### Theory of the proximity effect in junctions with unconventional superconductors

We present a general theory of the proximity effect in junctions between
diffusive normal metals (DN) and unconventional superconductors in the
framework of the quasiclassical Green's function formalism. Various possible
symmetry classes in a superconductor are considered which are consistent with
the Pauli principle: even-frequency spin-singlet even-parity (ESE) state,
even-frequency spin-triplet odd-parity (ETO) state, odd-frequency spin-triplet
even-parity (OTE) state and odd-frequency spin-singlet odd-parity (OSO) state.
For each of the above four cases symmetry and spectral properties of the
induced pair amplitude in the DN are determined. It is shown that the pair
amplitude in a DN belongs respectively to an ESE, OTE, OTE and ESE pairing
state.Comment: 5 pages with one figur

### X-ray astronomy program in Japan

Hakucho satellite operations and the problems that emerged from the neutron star observations are illustrated. X-ray pulsars and bursters are reviewed. Future satellite programs are outlined

### Temperature-dependence of spin-polarized transport in ferromagnet / unconventional superconductor junctions

Tunneling conductance in ferromagnet / unconventional superconductor
junctions is studied theoretically as a function of temperatures and
spin-polarization in feromagnets. In d-wave superconductor junctions, the
existence of a zero-energy Andreev bound state drastically affects the
temperature-dependence of the zero-bias conductance (ZBC). In p-wave triplet
superconductor junctions, numerical results show a wide variety in
temperature-dependence of the ZBC depending on the direction of the magnetic
moment in ferromagnets and the pairing symmetry in superconductors such as
$p_{x}$, $p_{y}$ and $p_{x}+ip_{y}$-wave pair potential. The last one is a
promising symmetry of Sr$_2$RuO$_4$. From these characteristic features in the
conductance, we may obtain the information about the degree of
spin-polarization in ferromagnets and the direction of the $d$-vector in
triplet superconductors

### A Mean-field Approach for an Intercarrier Interference Canceller for OFDM

The similarity of the mathematical description of random-field spin systems
to orthogonal frequency-division multiplexing (OFDM) scheme for wireless
communication is exploited in an intercarrier-interference (ICI) canceller used
in the demodulation of OFDM. The translational symmetry in the Fourier domain
generically concentrates the major contribution of ICI from each subcarrier in
the subcarrier's neighborhood. This observation in conjunction with mean field
approach leads to a development of an ICI canceller whose necessary cost of
computation scales linearly with respect to the number of subcarriers. It is
also shown that the dynamics of the mean-field canceller are well captured by a
discrete map of a single macroscopic variable, without taking the spatial and
time correlations of estimated variables into account.Comment: 7pages, 3figure

- â€¦