318 research outputs found
thermal Josephson junction
We predict the thermal counterpart of the anomalous Josephson effect in
superconductor/ferromagnet/superconductor junctions with non-coplanar magnetic
texture. The heat current through the junction is shown to have the
phase-sensitive interference component proportional to , where is the Josephson phase difference and is
the texture-dependent phase shift. In the generic tri-layer magnetic structure
with the spin-filtering tunnel barrier is determined by the spin
chirality of magnetic configuration and can be considered as the direct
manifestation of the energy transport with participation of spin-triplet Cooper
pairs. In case of the ideal spin filter the phase shift is shown to be robust
against spin relaxation caused by the spin-orbital scattering. Possible
applications of the coupling between heat flow and magnetic precession are
discussed.Comment: In this version new references adde
Field dependence of the vortex-core sizes in dirty two-band superconductors
We study the structure of Abrikosov vortices in two-band superconductors for
different external magnetic fields and different parameters of the bands. The
vortex core size determined by the coherence lengths are found to have
qualitatively different behaviour from that determined by the quasiparticle
density of states spatial variation. These different vortex core length scales
coincide near the upper critical field, while the discrepancy between them
becomes quite significant at lower fields. Within the diffusive approximation
we demonstrate several generic regimes in the field dependence of the vortex
core sizes determined by the disparity of diffusion constants in the two bands.Comment: 6 pages, 5 figure
Lifshitz transition in the double-core vortex in 3He-B
We study the spectrum of fermion states localized within the vortex core of a
weak-coupling p-wave superfluid. The low energy spectrum consists of two
anomalous branches that cross the Fermi level as functions of the impact
parameter, and generate large density of states at the locations of the half
cores of the vortex. Fermi liquid interactions significantly change the vortex
structure, which leads to Lifshitz transition in the effective Fermi surface of
the vortex core fermions. We apply the results to revise the interpretation of
an experiment on rotational dynamics of vortices in superfluid 3He-B.Comment: 11 pages, 6 figures, updated to the published versio
Spin torques and magnetic texture dynamics driven by the supercurrent in superconductor/ferromagnet structures
We introduce the general formalism to describe spin torques induced by the
supercurrents injected from the adjacent superconducting electrodes into the
spin-textured ferromagnets. By considering the adiabatic limit for the
equal-spin superconducting correlations in the ferromagnet we show that the
supercurrent can generate both the field-like spin transfer torque and the
spin-orbital torque. These dissipationless spin torques are expressed through
the current-induced corrections to the effective field derived from the system
energy. The general formalism is applied to show that the supercurrent can
either shift or move the magnetic domain walls depending on their structure and
the type of spin-orbital interaction in the system. These results can be used
for the prediction and interpretation of the experiments studying magnetic
texture dynamics in superconductor/ferromagnet/superconductor Josephson
junctions and other hybrid structures.Comment: published version, some typos are correcte
Large enhancement of spin pumping due to the surface bound states in normal metal/superconductor structures
We show that the spin pumping from ferromagnetic insulator into the adjacent
metallic spin sink can be strongly stimulated by the superconducting
correlations.
The key physical mechanism responsible for this effect is the presence of
quasiparticle surface states at the ferromagnetic insulator/superconductor
interface. We consider the minimal model when these states appear because of
the suppressed pairing constant within the interfacial normal layer. For thin
normal layers we obtain a strongly peaked temperature dependence of the Gilbert
damping coefficient which has been recently observed in such systems. For
thicker normal layers the Gilbert damping monotonically increases down to the
temperatures much smaller than the critical one. The suggested model paves the
way to controlling the temperature dependence of the spin pumping by
fabricating hybrid normal metal/superconductor spin sinks
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