14 research outputs found
Strong asymmetry of microwave absorption by bi-layer conducting ferromagnetic films in the microstrip-line based broadband ferromagnetic resonance
Peculiarities of ferromagnetic resonance response of conducting magnetic
bi-layer films of nanometric thicknesses excited by microstrip microwave
transducers have been studied theoretically. Strong asymmetry of the response
has been found. Depending on the order of layers with respect to the transducer
either the first higher-order standing spin wave mode, or the fundamental mode
shows the largest response.
Film conductivity and lowered symmetry of microwave fields of such
transducers are responsible for this behavior. Amplitude of which mode is
larger also depends on the driving frequency. This effect is explained as
shielding of the asymmetric transducer field by eddy currents in the films.
This shielding remains very efficient for films with thicknesses well below the
microwave skin depth. This effect may be useful for studying buried magnetic
interfaces and should be accounted for in future development of broadband
inductive ferromagnetic resonance methods.Comment: 21 Page, 4 figure
Three-Body Halos in Two Dimensions
A method to study weakly bound three-body quantum systems in two dimensions
is formulated in coordinate space for short-range potentials. Occurrences of
spatially extended structures (halos) are investigated. Borromean systems are
shown to exist in two dimensions for a certain class of potentials. An
extensive numerical investigation shows that a weakly bound two-body state
gives rise to two weakly bound three-body states, a reminiscence of the Efimov
effect in three dimensions. The properties of these two states in the weak
binding limit turn out to be universal.
PACS number(s): 03.65.Ge, 21.45.+v, 31.15.Ja, 02.60NmComment: 9 pages, 2 postscript figures, LaTeX, epsf.st
Liberating Efimov physics from three dimensions
When two particles attract via a resonant short-range interaction, three
particles always form an infinite tower of bound states characterized by a
discrete scaling symmetry. It has been considered that this Efimov effect
exists only in three dimensions. Here we review how the Efimov physics can be
liberated from three dimensions by considering two-body and three-body
interactions in mixed dimensions and four-body interaction in one dimension. In
such new systems, intriguing phenomena appear, such as confinement-induced
Efimov effect, Bose-Fermi crossover in Efimov spectrum, and formation of
interlayer Efimov trimers. Some of them are observable in ultracold atom
experiments and we believe that this study significantly broadens our horizons
of universal Efimov physics.Comment: 17 pages, 5 figures, contribution to a special issue of Few-Body
Systems devoted to Efimov Physic