2 research outputs found
Evidences for magnetic dimers and skyrmion lattice formation in EuPdSn
Magnetic, thermal and transport properties of the non-centrosymmetric
compound EuPdSn are revisited after including new measurements. In its
paramagnetic phase, the outstanding feature of this compound is the formation
of Eu dimers that allows to understand the deviation of the magnetic
susceptibility from the C-W law below about 70\,K, the field
dependent magnetization variation below \,K and the reduced
entropy at the ordering temperature . A significant change
of the exchange interactions occurs between \,K (where \,K) and \,K (where \,K). The strong electronic
overlap, arising from the reduced Eu-Eu spacing compared with that of pure
Eu is expected to power these quasiparticles formation, inducing a
significant reformulation of the magnetic structure.
A rich magnetic phase diagram is obtained from the analysis of the
derivatives of the magnetic parameters: and
, and the field dependence of the specific heat. Two
critical points are recognized and a tentative description of the magnetic
structures is proposed. The possible formation of a skyrmion lattice, that
arises from the presence of magnetically frustrated pockets in the phase
diagram, is suggested by theoretical studies on hexagonal structures exhibiting
similar interactions pattern.Comment: 13 pages, 11 figure
Ring diagrams and electroweak phase transition in a magnetic field
Electroweak phase transition in a magnetic field is investigated within the
one-loop and ring diagram contributions to the effective potential in the
minimal Standard Model. All fundamental fermions and bosons are included with
their actual values of masses and the Higgs boson mass is considered in the
range . The effective potential is real at
sufficiently high temperature. The important role of fermions and -bosons in
symmetry behaviour is observed. It is found that the phase transition for the
field strengths G is of first order but the baryogenesis
condition is not satisfied. The comparison with the hypermagnetic field case is
done.Comment: 16 pages, Latex, changed for a mistake in the numerical par