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Четверг 22 ноября 2018 г.<br>
Теоретический семинар в ИФП, 11:30.<br>
<br>
<br>
Vladimir Krasnov (Stockholm University, Sweden)<br>
<br>
<font size="+1"><b>Josephson and non-Josephson emission from
Bi2Sr2CaCu2O8+δ mesa structures</b></font><br>
<br>
Mesa structures made of Bi2Sr2CaCu2O8+δ high-temperature
superconductor represent stacks of atomic scale intrinsic Josephson
junctions. When voltage is applied to such mesas, they can generate
various types of waves (photons, phonons, polaritons, magnons,
plasmons) in a variety of different ways. In this talk I will
overview both Josephson and non-Josephson mechanisms of emission,
including the standard ac-Josephson effect for emission of
electromagnetic waves [1], segnetoelectric effect for emission of
phonons and polaritons [2] and non-equilibrium quasiparticle
relaxation and recombination for emission of any type of bosons,
having strong electron-boson interaction and participating in
pairing [3]. Those effects are important both for applied research,
e.g., creation of tunable, compact, continuous wave and
monochromatic THz source with a frequency span in the whole THz gap
region and beyond 0.1-15 THz [1,2], and for fundamental
understanding of the mechanism of pairing in high-temperature
superconductors [3].<br>
<br>
1. E. A. Borodianskyi and V.M. Krasnov, Josephson emission with
frequency span 1–11 THz from small Bi2Sr2CaCu2O8+δ mesa structures,
Nature Commun. 8, 1742 (2017).<br>
2. S. O. Katterwe, H. Motzkau, A. Rydh, and V. M. Krasnov, Coherent
generation of phonon-polaritons in Bi2Sr2CaCu2O8+x intrinsic
Josephson junctions, Phys. Rev. B 83, 100510(R) (2011).<br>
3. V.M. Krasnov, S.O. Katterwe, & A. Rydh, Signatures of the
electronic nature of pairing in high-Tc superconductors obtained by
non-equilibrium boson spectroscopy, Nature Commun. 4, 2970 (2013).<br>
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Информация о всех запланированных семинарах:<br>
<a href="http://itp.ac.ru/ru/seminars/kapitza-institute/">http://itp.ac.ru/ru/seminars/kapitza-institute/</a><br>
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