4,132 research outputs found
Magnetic field dependence of pairing interaction in ferromagnetic superconductors with triplet pairing
It is developed a microscopic description of superconductivity in
ferromagnetic materials with triplet pairing triggered by the exchange of
magnetic fluctuations. Instead widely used paramagnon model we work with
phenomenological spectrum of fluctuations in the orthorhombic ferromagnet with
strong magnetic anisotropy. Depending of the field orientation parallel or
perpendicular to the direction of spontaneous magnetization the effective
amplitude of pairing interaction proves to be decreasing or increasing function
of magnetic field that allows to explain the drastic difference in magnitudes
of upper critical field in these directions.Comment: 9 pages, no figure
Nonuniform states in noncentrosymmetric superconductors
In noncentrosymmetric crystals, nonuniform superconducting states are
possible even in the absence of any external magnetic field. The origin of
these states can be traced to the Lifshitz invariants in the free energy, which
are linear in spatial gradients. We show how various types of the Lifshitz
invariants in noncentrosymmetric superconductors can be derived from
microscopic theory.Comment: 7 page
On the theory of polarized Fermi liquid
The transport equation for transverse vibrations of magnetization in spin
polarized Fermi liquid is derived from integral equation for the vertex
function. The dispersion law for the transverse spin waves is established. The
existance of zero-temperature spin-waves attenuation is confirmed. The problem
of similar derivation in ferromagnetic "Fermi liquid" is discussed.Comment: 3 pages, no figure
Superconductivity in Uranium Ferromagnets
The theoretical description and the survey of physical properties of
superconducting states in the uranium ferromagnetic materials are presented. On
the basis of microscopic theory is shown that the coupling between the
electrons in these ferromagnetic metals by means of magnetization fluctuations
gives rise the triplet pairing superconducting state and the general form of
the order parameter dictated by the symmetry is established.
The theory allows to explain some specific observations including peculiar
phenomenon of reentrant superconductivity in URhGe in magnetic field
perpendicular to the direction of spontaneous magnetization.
In addition we describe several particular topics relating to uranium
superconducting ferromagnets: (i) critical magnetic relaxation in dual
localized-itinerant ferromagnets, (ii) phase transition to ferromagnetic state
in Fermi liquid and UGe, (iii) superconducting ordering in ferromagnetic
metals without inversion symmetry.Comment: 56 pages, 19 figure
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