8,669 research outputs found
Common Fermi-liquid origin of T-squared resistivity and superconductivity in n-type SrTiO3
A detailed analysis is given of the T^2 term in the resistivity observed in
electron-doped SrTiO3. Novel bandstructure data are presented, which provide
values for the bare mass, density of states, and plasma frequency of the
quasiparticles as a function of doping. It is shown that these values are
renormalized by approximately a factor 2 due to electron-phonon interaction. It
is argued that the quasiparticles are in the anti-adiabatic limit with respect
to electron-phonon interaction. The condition of anti-adiabatic coupling
renders the interaction mediated through phonons effectively non-retarded. We
apply Fermi-liquid theory developed in the 70's for the T^2 term in the
resistivity of common metals, and combine this with expressions for Tc and with
the Brinkman-Platzman-Rice (BPR) sum-rule to obtain Landau parameters of n-type
SrTiO3. These parameters are comparable to those of liquid 3He, indicating
interesting parallels between these Fermi-liquids despite the differences
between the composite fermions from which they are formed.Comment: 12 pages, 9 figure
Stratified dispersive model for material characterization using terahertz time-domain spectroscopy
We propose a novel THz material analysis approach which provides highly
accurate material parameters and can be used for industrial quality control.
The method treats the inspected material within its environment locally as a
stratified system and describes the light-matter interaction of each layer in a
realistic way. The approach is illustrated in the time-domain and
frequency-domain for two potential fields of implementation of THz technology:
quality control of (coated) paper sheets and car paint multilayers, both
measured in humid air.Comment: 4 pages, 4 figure
Spin resonance in EuTiO3 probed by time-domain GHz ellipsometry
We show an example of a purely magnetic spin resonance in EuTiO3 and the
resulting new record high Faraday rotation of 590 deg/mm at 1.6 T for 1 cm
wavelengths probed by a novel technique of magneto-optical GHz time-domain
ellipsometry. From our transmission measurements of linear polarized light we
map out the complex index of refraction in the GHz to THz range. We observe a
strong resonant absorption by magnetic dipole transitions involving the Zeeman
split S=7/2 magnetic energy levels of the Eu 2+ ions, which causes a very large
dichroism for circular polarized radiation.Comment: 4 pages, 4 figure
Institutional and other platforms
This chapters pays attention to the intervention of media art in mass media in the eighties and later on and to the specialist and more traditional art institutions
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