1,621 research outputs found
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
Influence of the atomic-scale inhomogeneity of the pair interaction on extracted from the STM spectra characteristics of high- superconductors
The influence of the atomic-scale inhomogeneities of the pairing interaction
strength on the superconducting order parameter and the conductance spectra
measurable by STM is studied in the framework of weak-coupling BCS-like theory
for two-dimensional lattice model. First of all, it is found that the
inhomogeneity having the form of atomic-scale regions of enhanced pair
interaction increases the ratio of the local low-temperature gap in
differential conductance spectra to the local temperature of vanishing the gap
. Even in the framework of mean-field treatment this ratio is
shown to be larger than the one corresponding to the homogeneous case. It is
shown that the effect of thermal phase fluctuations of the superconducting
order parameter can further increase this ratio. Taking them into account in
the framework of a toy model we obtained the ratio to be . It is found that the additional atomic-scale hopping element disorder and
weak potential scatterers, which can also take place in cuprate materials, have
no considerable effect on the statistical properties of the system, including
the distribution of the gaps, and the ratio . The second
consequence of the atomic-scale order parameter inhomogeneity is the
anticorrelation between the low-temperature gap and the high-temperature
zero-bias conductance. The obtained results could bear a relation to recent STM
measurements.Comment: 14 pages, 13 figure
- …