Temperature dependence of geometrical and velocity matching resonances in Bi2Sr2CaCu2O8+x intrinsic Josephson junctions
(English)Manuscript (preprint) (Other academic)
We study temperature dependence of geometrical (Fiske) and velocity-matching (Eck) resonances in the flux flow state of small Bi2Sr2CaCu2O8+x mesa structures. It is shown that the quality factor of resonances is high at low T, but rapidly decreases with increasing temperature already at T > 10 K. This indicates that self-heatingis strongly detrimental for operation of mesas as coherent THz oscillators and ultimately limits the emission power via suppression of the quality factor. We also study T-dependence of the resonant voltage and the speed of electromagnetic waves (Swihart velocity). Surprisingly it is observed that the Swihart velocity exhibits very weak T-dependence at low T, following T−dependence of the Josephson plasma frequency, rather than the expected linear T-dependence of the London penetration depth.
Condensed Matter Physics
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-62580OAI: oai:DiVA.org:su-62580DiVA: diva2:443113