title: Tunable terahertz emission from the intrinsic Josephson junctions in acute isosceles triangular Bi₂Sr₂CaCu₂O₈+δ mesas.
abstract: In order to determine if the mesa geometry might affect the properties of the coherent terahertz (THz) radiation emitted from the intrinsic Josephson junctions in mesas constructed from single crystals of the high-temperature superconductor, Bi₂Sr₂CaCu₂O₈+δ, we studied triangular mesas. For equilateral triangular mesas, the observed emission was found to be limited to the single mesa TM(1,0) mode. However, tunable radiation over the range from 0.495 to 0.934 THz was found to arise from an acute isosceles triangular mesa. This 47% tunability is the widest yet observed from the outer current-voltage characteristic branch of such mesas of any geometry. Although the radiation at a few of the frequencies in the tunable range appear to have been enhanced by cavity resonances, most frequencies are far from such resonance frequencies, and can only be attributed to the ac-Josephson effect.
authors: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8573, Japan. s-kaveh@ims.tsukuba.ac.jp
authors: K
authors: K
authors: Delfanazari
authors: H
authors: H
authors: Asai
authors: M
authors: M
authors: Tsujimoto
authors: T
authors: T
authors: Kashiwagi
authors: T
authors: T
authors: Kitamura
authors: T
authors: T
authors: Yamamoto
authors: M
authors: M
authors: Sawamura
authors: K
authors: K
authors: Ishida
authors: C
authors: C
authors: Watanabe
authors: S
authors: S
authors: Sekimoto
authors: H
authors: H
authors: Minami
authors: M
authors: M
authors: Tachiki
authors: R A
authors: RA
authors: Klemm
authors: T
authors: T
authors: Hattori
authors: K
authors: K
authors: Kadowaki
mesh_terms: D002516:Ceramics / Q000737:chemistry* / Q000528:radiation effects; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation*; D012666:Semiconductors; D055053:Terahertz Radiation