Temperature dependences of geometrical and velocity-matching resonances in Bi(2)Sr(2)CaCu(2)O(8+x) intrinsic Josephson junctions
2011 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 84, no 21, 214519- p.Article in journal (Refereed) Published
We study temperature dependence of geometrical (Fiske) and velocity-matching (Eck) resonances in the flux-flow state of small Bi(2)Sr(2)CaCu(2)O(8+x) mesa structures. It is shown that the quality factor of resonances is high at low T, but rapidly decreases with increasing temperature. We also study T dependencies of resonant voltages and the speed of electromagnetic waves (the Swihart velocity). Surprisingly it is observed that the Swihart velocity exhibits a flat T dependence at low T, following T dependence of the c-axis critical current, rather than the expected linear T dependence of the London penetration depth. Our data indicate that self-heating is detrimental for operation of mesas as coherent THz oscillators because it limits the emission power via suppression of the quality factor. On the other hand, significant temperature dependence of the Swihart velocity allows broad-range tunability of the output frequency.
Place, publisher, year, edition, pages
2011. Vol. 84, no 21, 214519- p.
IdentifiersURN: urn:nbn:se:su:diva-71130DOI: 10.1103/PhysRevB.84.214519ISI: 000298486500004OAI: oai:DiVA.org:su-71130DiVA: diva2:483985
authorCount :22012-01-262012-01-262012-01-26Bibliographically approved