580 research outputs found
A relaxation scheme for computation of the joint spectral radius of matrix sets
The problem of computation of the joint (generalized) spectral radius of
matrix sets has been discussed in a number of publications. In the paper an
iteration procedure is considered that allows to build numerically Barabanov
norms for the irreducible matrix sets and simultaneously to compute the joint
spectral radius of these sets.Comment: 16 pages, 2 figures, corrected typos, accepted for publication in
JDE
d-Wave Pairing in an Ensemble of Spin Polaron Quasiparticles in the Spin-Fermion Model of the Electronic Structure of the CuO2 Plane
It is demonstrated for the first time that the strong coupling between spin
moments of copper ions and oxygen holes, which arises upon hybridazation mixing
of two hole subsystems in the Emery model, not only affects the formation of
spin polaron quasiparticles but also ensures effective attraction between them
via the exchange interaction. This results in the Cooper instability with
d-wave pairing in a 2D ensemble of spin polaron quasiparticles. The T-x-phase
diagram obtained using this approach agrees well with the available
experimental data
Thermodynamics of symmetric spin--orbital model: One- and two-dimensional cases
The specific heat and susceptibilities for the two- and one-dimensional
spin--orbital models are calculated in the framework of a spherically symmetric
self-consistent approach at different temperatures and relations between the
parameters of the system. It is shown that even in the absence of the
long-range spin and orbital order, the system exhibits the features in the
behavior of thermodynamic characteristics, which are typical of those
manifesting themselves at phase transitions. Such features are attributed to
the quantum entanglement of the coupled spin and orbital degrees of freedom.Comment: 7 pages, 9 figures, submitted to JETP Letter
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