Spectral investigation of hot spot and cavity resonance effects on the terahertz radiation from high-T-c superconducting Bi2Sr2CaCu2O8+delta mesas
Abbreviated Journal Title
J. Phys.-Condes. Matter
terahertz emission; high temperature superconductivity; Josephson; junctions; synchronization; mesa arrays; hot spots; INTRINSIC JOSEPHSON-JUNCTIONS; THZ RADIATION; EMISSION; EMITTERS; Physics, Condensed Matter
Terahertz (THz) electromagnetic radiation emitted from single and series-connected rectangular mesa devices of high-T-c superconducting Bi2Sr2CaCu2O8+delta is investigated spectroscopically during simultaneous temperature distribution observations using a microcrystalline SiC photoluminescence technique. In single mesas, a hot-spot region with its temperature T locally exceeding T-c was observed to jump suddenly in position under small current I-bias changes. Although these hot-spot position jumps cause large changes in the output power with small changes in I, as long as the voltage V per junction number N is kept constant, they do not affect the output frequency f, which is given by the ac Josephson frequency f(J). f can lock onto that of a particular mesa cavity resonance frequency f(c), which enhances the emission power and serves as the primary mechanism for the synchronization of the emissions from each of the intrinsic Josephson junctions in the mesa.
Journal of Physics-Condensed Matter
"Spectral investigation of hot spot and cavity resonance effects on the terahertz radiation from high-T-c superconducting Bi2Sr2CaCu2O8+delta mesas" (2014). Faculty Bibliography 2010s. 6262.